From 9178394dd6d2f0ca4d727445e608d058ed160dac Mon Sep 17 00:00:00 2001
From: Jakob Ackermann <jakob.ackermann@overleaf.com>
Date: Tue, 13 Jul 2021 12:04:43 +0100
Subject: [PATCH] [misc] run format_fix and lint:fix

---
 services/track-changes/app.js                 |  12 +-
 .../track-changes/app/js/DiffGenerator.js     |  31 +-
 services/track-changes/app/js/DiffManager.js  |  50 +-
 .../app/js/DocumentUpdaterManager.js          |   6 +-
 .../track-changes/app/js/HealthChecker.js     |  64 +-
 .../track-changes/app/js/HttpController.js    | 126 ++--
 services/track-changes/app/js/LockManager.js  |  69 +-
 services/track-changes/app/js/MongoAWS.js     |  54 +-
 services/track-changes/app/js/MongoManager.js | 108 +--
 services/track-changes/app/js/PackManager.js  | 423 ++++++-----
 services/track-changes/app/js/PackWorker.js   |  16 +-
 .../track-changes/app/js/ProjectIterator.js   | 180 ++---
 services/track-changes/app/js/RedisManager.js |  46 +-
 .../track-changes/app/js/RestoreManager.js    |   2 +-
 .../track-changes/app/js/UpdateCompressor.js  |  64 +-
 .../track-changes/app/js/UpdateTrimmer.js     |  93 +--
 .../track-changes/app/js/UpdatesManager.js    | 713 +++++++++---------
 .../track-changes/app/js/WebApiManager.js     |   8 +-
 services/track-changes/app/js/mongodb.js      |   2 +-
 .../track-changes/app/lib/diff_match_patch.js |  27 +-
 .../track-changes/config/settings.defaults.js |  38 +-
 .../acceptance/js/AppendingUpdatesTests.js    | 114 +--
 .../acceptance/js/ArchivingUpdatesTests.js    |  56 +-
 .../acceptance/js/FlushingUpdatesTests.js     |  58 +-
 .../test/acceptance/js/GettingADiffTests.js   |  22 +-
 .../test/acceptance/js/GettingUpdatesTests.js |  40 +-
 .../test/acceptance/js/LockManagerTests.js    |   8 +-
 .../test/acceptance/js/RestoringVersions.js   |  18 +-
 .../acceptance/js/helpers/MockDocStoreApi.js  |   6 +-
 .../js/helpers/MockDocUpdaterApi.js           |   6 +-
 .../test/acceptance/js/helpers/MockWebApi.js  |   6 +-
 .../acceptance/js/helpers/TrackChangesApp.js  |   6 +-
 .../js/helpers/TrackChangesClient.js          |  42 +-
 services/track-changes/test/setup.js          |   6 +-
 .../js/DiffGenerator/DiffGeneratorTests.js    |  94 +--
 .../unit/js/DiffManager/DiffManagerTests.js   |  26 +-
 .../test/unit/js/DocArchive/MongoAWS.js       |  12 +-
 .../DocumentUpdaterManagerTests.js            |  12 +-
 .../js/HttpController/HttpControllerTests.js  |  34 +-
 .../unit/js/LockManager/LockManagerTests.js   |  12 +-
 .../unit/js/MongoManager/MongoManagerTests.js |  18 +-
 .../unit/js/PackManager/PackManagerTests.js   |  60 +-
 .../unit/js/RedisManager/RedisManagerTests.js |  20 +-
 .../js/RestoreManager/RestoreManagerTests.js  |   4 +-
 .../UpdateCompressor/UpdateCompressorTests.js | 356 ++++-----
 .../js/UpdateTrimmer/UpdateTrimmerTests.js    |   4 +-
 .../js/UpdatesManager/UpdatesManagerTests.js  | 266 +++----
 .../js/WebApiManager/WebApiManagerTests.js    |  22 +-
 48 files changed, 1742 insertions(+), 1718 deletions(-)

diff --git a/services/track-changes/app.js b/services/track-changes/app.js
index 4245231b8d..a009431de0 100644
--- a/services/track-changes/app.js
+++ b/services/track-changes/app.js
@@ -16,7 +16,7 @@ if ((Settings.sentry != null ? Settings.sentry.dsn : undefined) != null) {
 }
 
 // log updates as truncated strings
-const truncateFn = (updates) =>
+const truncateFn = updates =>
   JSON.parse(
     JSON.stringify(updates, function (key, value) {
       let len
@@ -35,7 +35,7 @@ TrackChangesLogger.addSerializers({
   rawUpdate: truncateFn,
   rawUpdates: truncateFn,
   newUpdates: truncateFn,
-  lastUpdate: truncateFn
+  lastUpdate: truncateFn,
 })
 
 const Path = require('path')
@@ -91,7 +91,7 @@ app.post('/pack', function (req, res, next) {
       [
         req.query.limit || 1000,
         req.query.delay || 1000,
-        req.query.timeout || 30 * 60 * 1000
+        req.query.timeout || 30 * 60 * 1000,
       ]
     )
     packWorker.on('exit', function (code, signal) {
@@ -120,12 +120,12 @@ app.use(function (error, req, res, next) {
 const port =
   __guard__(
     Settings.internal != null ? Settings.internal.trackchanges : undefined,
-    (x) => x.port
+    x => x.port
   ) || 3015
 const host =
   __guard__(
     Settings.internal != null ? Settings.internal.trackchanges : undefined,
-    (x1) => x1.host
+    x1 => x1.host
   ) || 'localhost'
 
 if (!module.parent) {
@@ -146,7 +146,7 @@ if (!module.parent) {
         }
       })
     })
-    .catch((err) => {
+    .catch(err => {
       logger.fatal({ err }, 'Cannot connect to mongo. Exiting.')
       process.exit(1)
     })
diff --git a/services/track-changes/app/js/DiffGenerator.js b/services/track-changes/app/js/DiffGenerator.js
index ebc6a9fcb1..0d8ef0be94 100644
--- a/services/track-changes/app/js/DiffGenerator.js
+++ b/services/track-changes/app/js/DiffGenerator.js
@@ -162,13 +162,11 @@ module.exports = DiffGenerator = {
     if (op.i != null) {
       newDiff.push({
         i: op.i,
-        meta
+        meta,
       })
     } else if (op.d != null) {
-      ;({
-        consumedDiff,
-        remainingDiff
-      } = DiffGenerator._consumeDiffAffectedByDeleteOp(remainingDiff, op, meta))
+      ;({ consumedDiff, remainingDiff } =
+        DiffGenerator._consumeDiffAffectedByDeleteOp(remainingDiff, op, meta))
       newDiff.push(...Array.from(consumedDiff || []))
     }
 
@@ -211,7 +209,7 @@ module.exports = DiffGenerator = {
 
     return {
       consumedDiff,
-      remainingDiff
+      remainingDiff,
     }
   },
 
@@ -220,18 +218,15 @@ module.exports = DiffGenerator = {
     let remainingOp = deleteOp
     while (remainingOp && remainingDiff.length > 0) {
       let newPart
-      ;({
-        newPart,
-        remainingDiff,
-        remainingOp
-      } = DiffGenerator._consumeDeletedPart(remainingDiff, remainingOp, meta))
+      ;({ newPart, remainingDiff, remainingOp } =
+        DiffGenerator._consumeDeletedPart(remainingDiff, remainingOp, meta))
       if (newPart != null) {
         consumedDiff.push(newPart)
       }
     }
     return {
       consumedDiff,
-      remainingDiff
+      remainingDiff,
     }
   },
 
@@ -262,7 +257,7 @@ module.exports = DiffGenerator = {
       if (part.u != null) {
         newPart = {
           d: op.d,
-          meta
+          meta,
         }
       } else if (part.i != null) {
         newPart = null
@@ -282,7 +277,7 @@ module.exports = DiffGenerator = {
       if (part.u != null) {
         newPart = {
           d: op.d,
-          meta
+          meta,
         }
       } else if (part.i != null) {
         newPart = null
@@ -303,7 +298,7 @@ module.exports = DiffGenerator = {
       if (part.u) {
         newPart = {
           d: part.u,
-          meta
+          meta,
         }
       } else if (part.i != null) {
         newPart = null
@@ -311,14 +306,14 @@ module.exports = DiffGenerator = {
 
       remainingOp = {
         p: op.p,
-        d: op.d.slice(DiffGenerator._getLengthOfDiffPart(part))
+        d: op.d.slice(DiffGenerator._getLengthOfDiffPart(part)),
       }
     }
 
     return {
       newPart,
       remainingDiff,
-      remainingOp
+      remainingOp,
     }
   },
 
@@ -341,5 +336,5 @@ module.exports = DiffGenerator = {
 
   _getContentOfPart(part) {
     return part.u || part.d || part.i || ''
-  }
+  },
 }
diff --git a/services/track-changes/app/js/DiffManager.js b/services/track-changes/app/js/DiffManager.js
index a33ed07c2d..7c8a9d4ceb 100644
--- a/services/track-changes/app/js/DiffManager.js
+++ b/services/track-changes/app/js/DiffManager.js
@@ -24,30 +24,30 @@ module.exports = DiffManager = {
     if (callback == null) {
       callback = function (error, content, version, updates) {}
     }
-    return DocumentUpdaterManager.getDocument(project_id, doc_id, function (
-      error,
-      content,
-      version
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      if (fromVersion == null) {
-        // If we haven't been given a version, just return lastest doc and no updates
-        return callback(null, content, version, [])
-      }
-      return UpdatesManager.getDocUpdatesWithUserInfo(
-        project_id,
-        doc_id,
-        { from: fromVersion },
-        function (error, updates) {
-          if (error != null) {
-            return callback(error)
-          }
-          return callback(null, content, version, updates)
+    return DocumentUpdaterManager.getDocument(
+      project_id,
+      doc_id,
+      function (error, content, version) {
+        if (error != null) {
+          return callback(error)
         }
-      )
-    })
+        if (fromVersion == null) {
+          // If we haven't been given a version, just return lastest doc and no updates
+          return callback(null, content, version, [])
+        }
+        return UpdatesManager.getDocUpdatesWithUserInfo(
+          project_id,
+          doc_id,
+          { from: fromVersion },
+          function (error, updates) {
+            if (error != null) {
+              return callback(error)
+            }
+            return callback(null, content, version, updates)
+          }
+        )
+      }
+    )
   },
 
   getDiff(project_id, doc_id, fromVersion, toVersion, callback) {
@@ -167,7 +167,7 @@ module.exports = DiffManager = {
           {
             docVersion: version,
             lastUpdateVersion: lastUpdate != null ? lastUpdate.v : undefined,
-            updateCount: updates.length
+            updateCount: updates.length,
           },
           'rewinding updates'
         )
@@ -184,5 +184,5 @@ module.exports = DiffManager = {
         return callback(null, startingContent, tryUpdates)
       }
     )
-  }
+  },
 }
diff --git a/services/track-changes/app/js/DocumentUpdaterManager.js b/services/track-changes/app/js/DocumentUpdaterManager.js
index e3a7c2ce10..01cdf9e07c 100644
--- a/services/track-changes/app/js/DocumentUpdaterManager.js
+++ b/services/track-changes/app/js/DocumentUpdaterManager.js
@@ -65,8 +65,8 @@ module.exports = DocumentUpdaterManager = {
           lines: content.split('\n'),
           source: 'restore',
           user_id,
-          undoing: true
-        }
+          undoing: true,
+        },
       },
       function (error, res, body) {
         if (error != null) {
@@ -86,5 +86,5 @@ module.exports = DocumentUpdaterManager = {
         }
       }
     )
-  }
+  },
 }
diff --git a/services/track-changes/app/js/HealthChecker.js b/services/track-changes/app/js/HealthChecker.js
index 7a645b254d..94ba2371a8 100644
--- a/services/track-changes/app/js/HealthChecker.js
+++ b/services/track-changes/app/js/HealthChecker.js
@@ -24,7 +24,7 @@ module.exports = {
     const url = `http://localhost:${port}/project/${project_id}`
     logger.log({ project_id }, 'running health check')
     const jobs = [
-      (cb) =>
+      cb =>
         request.get(
           { url: `http://localhost:${port}/check_lock`, timeout: 3000 },
           function (err, res, body) {
@@ -41,44 +41,42 @@ module.exports = {
             }
           }
         ),
-      (cb) =>
-        request.post({ url: `${url}/flush`, timeout: 10000 }, function (
-          err,
-          res,
-          body
-        ) {
-          if (err != null) {
-            logger.err({ err, project_id }, 'error flushing for health check')
-            return cb(err)
-          } else if ((res != null ? res.statusCode : undefined) !== 204) {
-            return cb(`status code not 204, it's ${res.statusCode}`)
-          } else {
-            return cb()
+      cb =>
+        request.post(
+          { url: `${url}/flush`, timeout: 10000 },
+          function (err, res, body) {
+            if (err != null) {
+              logger.err({ err, project_id }, 'error flushing for health check')
+              return cb(err)
+            } else if ((res != null ? res.statusCode : undefined) !== 204) {
+              return cb(`status code not 204, it's ${res.statusCode}`)
+            } else {
+              return cb()
+            }
           }
-        }),
-      (cb) =>
-        request.get({ url: `${url}/updates`, timeout: 10000 }, function (
-          err,
-          res,
-          body
-        ) {
-          if (err != null) {
-            logger.err(
-              { err, project_id },
-              'error getting updates for health check'
-            )
-            return cb(err)
-          } else if ((res != null ? res.statusCode : undefined) !== 200) {
-            return cb(`status code not 200, it's ${res.statusCode}`)
-          } else {
-            return cb()
+        ),
+      cb =>
+        request.get(
+          { url: `${url}/updates`, timeout: 10000 },
+          function (err, res, body) {
+            if (err != null) {
+              logger.err(
+                { err, project_id },
+                'error getting updates for health check'
+              )
+              return cb(err)
+            } else if ((res != null ? res.statusCode : undefined) !== 200) {
+              return cb(`status code not 200, it's ${res.statusCode}`)
+            } else {
+              return cb()
+            }
           }
-        })
+        ),
     ]
     return async.series(jobs, callback)
   },
 
   checkLock(callback) {
     return LockManager.healthCheck(callback)
-  }
+  },
 }
diff --git a/services/track-changes/app/js/HttpController.js b/services/track-changes/app/js/HttpController.js
index c5db48210a..8f665682eb 100644
--- a/services/track-changes/app/js/HttpController.js
+++ b/services/track-changes/app/js/HttpController.js
@@ -160,15 +160,18 @@ module.exports = HttpController = {
     }
 
     logger.log({ project_id, doc_id, from, to }, 'getting diff')
-    return DiffManager.getDiff(project_id, doc_id, from, to, function (
-      error,
-      diff
-    ) {
-      if (error != null) {
-        return next(error)
+    return DiffManager.getDiff(
+      project_id,
+      doc_id,
+      from,
+      to,
+      function (error, diff) {
+        if (error != null) {
+          return next(error)
+        }
+        return res.json({ diff })
       }
-      return res.json({ diff })
-    })
+    )
   },
 
   getUpdates(req, res, next) {
@@ -194,7 +197,7 @@ module.exports = HttpController = {
         }
         return res.json({
           updates,
-          nextBeforeTimestamp
+          nextBeforeTimestamp,
         })
       }
     )
@@ -207,60 +210,59 @@ module.exports = HttpController = {
     // Flush updates per pack onto the wire.
     const { project_id } = req.params
     logger.log({ project_id }, 'exporting project history')
-    UpdatesManager.exportProject(project_id, function (
-      err,
-      { updates, userIds },
-      confirmWrite
-    ) {
-      const abortStreaming = req.aborted || res.finished || res.destroyed
-      if (abortStreaming) {
-        // Tell the producer to stop emitting data
-        if (confirmWrite) confirmWrite(new Error('stop'))
-        return
-      }
-      const hasStartedStreamingResponse = res.headersSent
-      if (err) {
-        logger.error({ project_id, err }, 'export failed')
-        if (!hasStartedStreamingResponse) {
-          // Generate a nice 500
-          return next(err)
-        } else {
-          // Stop streaming
-          return res.destroy()
+    UpdatesManager.exportProject(
+      project_id,
+      function (err, { updates, userIds }, confirmWrite) {
+        const abortStreaming = req.aborted || res.finished || res.destroyed
+        if (abortStreaming) {
+          // Tell the producer to stop emitting data
+          if (confirmWrite) confirmWrite(new Error('stop'))
+          return
+        }
+        const hasStartedStreamingResponse = res.headersSent
+        if (err) {
+          logger.error({ project_id, err }, 'export failed')
+          if (!hasStartedStreamingResponse) {
+            // Generate a nice 500
+            return next(err)
+          } else {
+            // Stop streaming
+            return res.destroy()
+          }
+        }
+        // Compose the response incrementally
+        const isFirstWrite = !hasStartedStreamingResponse
+        const isLastWrite = updates.length === 0
+        if (isFirstWrite) {
+          // The first write will emit the 200 status, headers and start of the
+          //  response payload (open array)
+          res.setHeader('Content-Type', 'application/json')
+          res.setHeader('Trailer', 'X-User-Ids')
+          res.writeHead(200)
+          res.write('[')
+        }
+        if (!isFirstWrite && !isLastWrite) {
+          // Starting from the 2nd non-empty write, emit a continuing comma.
+          // write 1: [updates1
+          // write 2: ,updates2
+          // write 3: ,updates3
+          // write N: ]
+          res.write(',')
+        }
+
+        // Every write will emit a blob onto the response stream:
+        // '[update1,update2,...]'
+        //   ^^^^^^^^^^^^^^^^^^^
+        res.write(JSON.stringify(updates).slice(1, -1), confirmWrite)
+
+        if (isLastWrite) {
+          // The last write will have no updates and will finish the response
+          //  payload (close array) and emit the userIds as trailer.
+          res.addTrailers({ 'X-User-Ids': JSON.stringify(userIds) })
+          res.end(']')
         }
       }
-      // Compose the response incrementally
-      const isFirstWrite = !hasStartedStreamingResponse
-      const isLastWrite = updates.length === 0
-      if (isFirstWrite) {
-        // The first write will emit the 200 status, headers and start of the
-        //  response payload (open array)
-        res.setHeader('Content-Type', 'application/json')
-        res.setHeader('Trailer', 'X-User-Ids')
-        res.writeHead(200)
-        res.write('[')
-      }
-      if (!isFirstWrite && !isLastWrite) {
-        // Starting from the 2nd non-empty write, emit a continuing comma.
-        // write 1: [updates1
-        // write 2: ,updates2
-        // write 3: ,updates3
-        // write N: ]
-        res.write(',')
-      }
-
-      // Every write will emit a blob onto the response stream:
-      // '[update1,update2,...]'
-      //   ^^^^^^^^^^^^^^^^^^^
-      res.write(JSON.stringify(updates).slice(1, -1), confirmWrite)
-
-      if (isLastWrite) {
-        // The last write will have no updates and will finish the response
-        //  payload (close array) and emit the userIds as trailer.
-        res.addTrailers({ 'X-User-Ids': JSON.stringify(userIds) })
-        res.end(']')
-      }
-    })
+    )
   },
 
   restore(req, res, next) {
@@ -334,5 +336,5 @@ module.exports = HttpController = {
         return res.sendStatus(200)
       }
     })
-  }
+  },
 }
diff --git a/services/track-changes/app/js/LockManager.js b/services/track-changes/app/js/LockManager.js
index 6cdb03219a..8be04dbaae 100644
--- a/services/track-changes/app/js/LockManager.js
+++ b/services/track-changes/app/js/LockManager.js
@@ -43,19 +43,23 @@ module.exports = LockManager = {
       callback = function (err, gotLock) {}
     }
     const lockValue = LockManager.randomLock()
-    return rclient.set(key, lockValue, 'EX', this.LOCK_TTL, 'NX', function (
-      err,
-      gotLock
-    ) {
-      if (err != null) {
-        return callback(err)
+    return rclient.set(
+      key,
+      lockValue,
+      'EX',
+      this.LOCK_TTL,
+      'NX',
+      function (err, gotLock) {
+        if (err != null) {
+          return callback(err)
+        }
+        if (gotLock === 'OK') {
+          return callback(err, true, lockValue)
+        } else {
+          return callback(err, false)
+        }
       }
-      if (gotLock === 'OK') {
-        return callback(err, true, lockValue)
-      } else {
-        return callback(err, false)
-      }
-    })
+    )
   },
 
   getLock(key, callback) {
@@ -102,23 +106,26 @@ module.exports = LockManager = {
   },
 
   releaseLock(key, lockValue, callback) {
-    return rclient.eval(LockManager.unlockScript, 1, key, lockValue, function (
-      err,
-      result
-    ) {
-      if (err != null) {
-        return callback(err)
+    return rclient.eval(
+      LockManager.unlockScript,
+      1,
+      key,
+      lockValue,
+      function (err, result) {
+        if (err != null) {
+          return callback(err)
+        }
+        if (result != null && result !== 1) {
+          // successful unlock should release exactly one key
+          logger.error(
+            { key, lockValue, redis_err: err, redis_result: result },
+            'unlocking error'
+          )
+          return callback(new Error('tried to release timed out lock'))
+        }
+        return callback(err, result)
       }
-      if (result != null && result !== 1) {
-        // successful unlock should release exactly one key
-        logger.error(
-          { key, lockValue, redis_err: err, redis_result: result },
-          'unlocking error'
-        )
-        return callback(new Error('tried to release timed out lock'))
-      }
-      return callback(err, result)
-    })
+    )
   },
 
   runWithLock(key, runner, callback) {
@@ -129,7 +136,7 @@ module.exports = LockManager = {
       if (error != null) {
         return callback(error)
       }
-      return runner((error1) =>
+      return runner(error1 =>
         LockManager.releaseLock(key, lockValue, function (error2) {
           error = error1 || error2
           if (error != null) {
@@ -142,7 +149,7 @@ module.exports = LockManager = {
   },
 
   healthCheck(callback) {
-    const action = (releaseLock) => releaseLock()
+    const action = releaseLock => releaseLock()
     return LockManager.runWithLock(
       `HistoryLock:HealthCheck:host=${HOST}:pid=${PID}:random=${RND}`,
       action,
@@ -153,5 +160,5 @@ module.exports = LockManager = {
   close(callback) {
     rclient.quit()
     return rclient.once('end', callback)
-  }
+  },
 }
diff --git a/services/track-changes/app/js/MongoAWS.js b/services/track-changes/app/js/MongoAWS.js
index cc4001e9ed..f9e69b12c2 100644
--- a/services/track-changes/app/js/MongoAWS.js
+++ b/services/track-changes/app/js/MongoAWS.js
@@ -31,12 +31,12 @@ const createStream = function (streamConstructor, project_id, doc_id, pack_id) {
     accessKeyId: settings.trackchanges.s3.key,
     secretAccessKey: settings.trackchanges.s3.secret,
     endpoint: settings.trackchanges.s3.endpoint,
-    s3ForcePathStyle: settings.trackchanges.s3.pathStyle
+    s3ForcePathStyle: settings.trackchanges.s3.pathStyle,
   }
 
   return streamConstructor(new AWS.S3(AWS_CONFIG), {
     Bucket: settings.trackchanges.stores.doc_history,
-    Key: project_id + '/changes-' + doc_id + '/pack-' + pack_id
+    Key: project_id + '/changes-' + doc_id + '/pack-' + pack_id,
   })
 }
 
@@ -52,7 +52,7 @@ module.exports = MongoAWS = {
 
     const query = {
       _id: ObjectId(pack_id),
-      doc_id: ObjectId(doc_id)
+      doc_id: ObjectId(doc_id),
     }
 
     if (project_id == null) {
@@ -92,14 +92,14 @@ module.exports = MongoAWS = {
             doc_id,
             pack_id,
             origSize: uncompressedData.length,
-            newSize: buf.length
+            newSize: buf.length,
           },
           'compressed pack'
         )
         if (err != null) {
           return callback(err)
         }
-        upload.on('error', (err) => callback(err))
+        upload.on('error', err => callback(err))
         upload.on('finish', function () {
           Metrics.inc('archive-pack')
           logger.log({ project_id, doc_id, pack_id }, 'upload to s3 completed')
@@ -135,8 +135,8 @@ module.exports = MongoAWS = {
     const download = createStream(S3S.ReadStream, project_id, doc_id, pack_id)
 
     const inputStream = download
-      .on('open', (obj) => 1)
-      .on('error', (err) => callback(err))
+      .on('open', obj => 1)
+      .on('error', err => callback(err))
 
     const gunzip = zlib.createGunzip()
     gunzip.setEncoding('utf8')
@@ -150,7 +150,7 @@ module.exports = MongoAWS = {
 
     const outputStream = inputStream.pipe(gunzip)
     const parts = []
-    outputStream.on('error', (err) => callback(err))
+    outputStream.on('error', err => callback(err))
     outputStream.on('end', function () {
       let object
       logger.log({ project_id, doc_id, pack_id }, 'download from s3 completed')
@@ -169,29 +169,31 @@ module.exports = MongoAWS = {
       }
       return callback(null, object)
     })
-    return outputStream.on('data', (data) => parts.push(data))
+    return outputStream.on('data', data => parts.push(data))
   },
 
   unArchivePack(project_id, doc_id, pack_id, callback) {
     if (callback == null) {
       callback = function (error) {}
     }
-    return MongoAWS.readArchivedPack(project_id, doc_id, pack_id, function (
-      err,
-      object
-    ) {
-      if (err != null) {
-        return callback(err)
+    return MongoAWS.readArchivedPack(
+      project_id,
+      doc_id,
+      pack_id,
+      function (err, object) {
+        if (err != null) {
+          return callback(err)
+        }
+        Metrics.inc('unarchive-pack')
+        // allow the object to expire, we can always retrieve it again
+        object.expiresAt = new Date(Date.now() + 7 * DAYS)
+        logger.log({ project_id, doc_id, pack_id }, 'inserting object from s3')
+        return db.docHistory.insertOne(object, (err, confirmation) => {
+          if (err) return callback(err)
+          object._id = confirmation.insertedId
+          callback(null, object)
+        })
       }
-      Metrics.inc('unarchive-pack')
-      // allow the object to expire, we can always retrieve it again
-      object.expiresAt = new Date(Date.now() + 7 * DAYS)
-      logger.log({ project_id, doc_id, pack_id }, 'inserting object from s3')
-      return db.docHistory.insertOne(object, (err, confirmation) => {
-        if (err) return callback(err)
-        object._id = confirmation.insertedId
-        callback(null, object)
-      })
-    })
-  }
+    )
+  },
 }
diff --git a/services/track-changes/app/js/MongoManager.js b/services/track-changes/app/js/MongoManager.js
index bfcdcf1ddb..6dfdd46ce3 100644
--- a/services/track-changes/app/js/MongoManager.js
+++ b/services/track-changes/app/js/MongoManager.js
@@ -50,50 +50,53 @@ module.exports = MongoManager = {
     if (callback == null) {
       callback = function (error, update, version) {}
     }
-    return MongoManager.getLastCompressedUpdate(doc_id, function (
-      error,
-      update
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      if (update != null) {
-        if (update.broken) {
-          // marked as broken so we will force a new op
-          return callback(null, null)
-        } else if (update.pack != null) {
-          if (update.finalised) {
-            // no more ops can be appended
-            return callback(
-              null,
-              null,
-              update.pack[0] != null ? update.pack[0].v : undefined
-            )
+    return MongoManager.getLastCompressedUpdate(
+      doc_id,
+      function (error, update) {
+        if (error != null) {
+          return callback(error)
+        }
+        if (update != null) {
+          if (update.broken) {
+            // marked as broken so we will force a new op
+            return callback(null, null)
+          } else if (update.pack != null) {
+            if (update.finalised) {
+              // no more ops can be appended
+              return callback(
+                null,
+                null,
+                update.pack[0] != null ? update.pack[0].v : undefined
+              )
+            } else {
+              return callback(
+                null,
+                update,
+                update.pack[0] != null ? update.pack[0].v : undefined
+              )
+            }
           } else {
-            return callback(
-              null,
-              update,
-              update.pack[0] != null ? update.pack[0].v : undefined
-            )
+            return callback(null, update, update.v)
           }
         } else {
-          return callback(null, update, update.v)
+          return PackManager.getLastPackFromIndex(
+            doc_id,
+            function (error, pack) {
+              if (error != null) {
+                return callback(error)
+              }
+              if (
+                (pack != null ? pack.inS3 : undefined) != null &&
+                (pack != null ? pack.v_end : undefined) != null
+              ) {
+                return callback(null, null, pack.v_end)
+              }
+              return callback(null, null)
+            }
+          )
         }
-      } else {
-        return PackManager.getLastPackFromIndex(doc_id, function (error, pack) {
-          if (error != null) {
-            return callback(error)
-          }
-          if (
-            (pack != null ? pack.inS3 : undefined) != null &&
-            (pack != null ? pack.v_end : undefined) != null
-          ) {
-            return callback(null, null, pack.v_end)
-          }
-          return callback(null, null)
-        })
       }
-    })
+    )
   },
 
   backportProjectId(project_id, doc_id, callback) {
@@ -103,10 +106,10 @@ module.exports = MongoManager = {
     return db.docHistory.updateMany(
       {
         doc_id: ObjectId(doc_id.toString()),
-        project_id: { $exists: false }
+        project_id: { $exists: false },
       },
       {
-        $set: { project_id: ObjectId(project_id.toString()) }
+        $set: { project_id: ObjectId(project_id.toString()) },
       },
       callback
     )
@@ -118,7 +121,7 @@ module.exports = MongoManager = {
     }
     return db.projectHistoryMetaData.findOne(
       {
-        project_id: ObjectId(project_id.toString())
+        project_id: ObjectId(project_id.toString()),
       },
       callback
     )
@@ -130,13 +133,13 @@ module.exports = MongoManager = {
     }
     return db.projectHistoryMetaData.updateOne(
       {
-        project_id: ObjectId(project_id)
+        project_id: ObjectId(project_id),
       },
       {
-        $set: metadata
+        $set: metadata,
       },
       {
-        upsert: true
+        upsert: true,
       },
       callback
     )
@@ -151,11 +154,11 @@ module.exports = MongoManager = {
       {
         project_id: ObjectId(project_id),
         temporary: true,
-        expiresAt: { $exists: true }
+        expiresAt: { $exists: true },
       },
       {
         $set: { temporary: false },
-        $unset: { expiresAt: '' }
+        $unset: { expiresAt: '' },
       },
       callback
     )
@@ -191,12 +194,9 @@ module.exports = MongoManager = {
       { project_id: 1 },
       { background: true }
     )
-  }
+  },
 }
-;[
-  'getLastCompressedUpdate',
-  'getProjectMetaData',
-  'setProjectMetaData'
-].map((method) =>
-  metrics.timeAsyncMethod(MongoManager, method, 'mongo.MongoManager', logger)
+;['getLastCompressedUpdate', 'getProjectMetaData', 'setProjectMetaData'].map(
+  method =>
+    metrics.timeAsyncMethod(MongoManager, method, 'mongo.MongoManager', logger)
 )
diff --git a/services/track-changes/app/js/PackManager.js b/services/track-changes/app/js/PackManager.js
index 509ba3e1c7..f8efb77f11 100644
--- a/services/track-changes/app/js/PackManager.js
+++ b/services/track-changes/app/js/PackManager.js
@@ -206,11 +206,11 @@ module.exports = PackManager = {
       sz,
       meta: {
         start_ts: first.meta.start_ts,
-        end_ts: last.meta.end_ts
+        end_ts: last.meta.end_ts,
       },
       v: first.v,
       v_end: last.v,
-      temporary
+      temporary,
     }
     if (temporary) {
       newPack.expiresAt = new Date(Date.now() + 7 * DAYS)
@@ -252,20 +252,20 @@ module.exports = PackManager = {
       _id: lastUpdate._id,
       project_id: ObjectId(project_id.toString()),
       doc_id: ObjectId(doc_id.toString()),
-      pack: { $exists: true }
+      pack: { $exists: true },
     }
     const update = {
       $push: {
-        pack: { $each: newUpdates }
+        pack: { $each: newUpdates },
       },
       $inc: {
         n: n,
-        sz: sz
+        sz: sz,
       },
       $set: {
         'meta.end_ts': last.meta.end_ts,
-        v_end: last.v
-      }
+        v_end: last.v,
+      },
     }
     if (lastUpdate.expiresAt && temporary) {
       update.$set.expiresAt = new Date(Date.now() + 7 * DAYS)
@@ -396,7 +396,7 @@ module.exports = PackManager = {
           }
           return result1
         })()
-        const loadedPackIds = Array.from(loadedPacks).map((pack) =>
+        const loadedPackIds = Array.from(loadedPacks).map(pack =>
           pack._id.toString()
         )
         const packIdsToFetch = _.difference(allPackIds, loadedPackIds)
@@ -494,7 +494,7 @@ module.exports = PackManager = {
       return db.docHistory.updateOne(
         { _id: pack._id },
         { $set: { expiresAt: new Date(Date.now() + 7 * DAYS) } },
-        (err) => callback(err, pack)
+        err => callback(err, pack)
       )
     } else {
       return callback(null, pack)
@@ -552,60 +552,62 @@ module.exports = PackManager = {
   },
 
   initialiseIndex(project_id, doc_id, callback) {
-    return PackManager.findCompletedPacks(project_id, doc_id, function (
-      err,
-      packs
-    ) {
-      // console.log 'err', err, 'packs', packs, packs?.length
-      if (err != null) {
-        return callback(err)
+    return PackManager.findCompletedPacks(
+      project_id,
+      doc_id,
+      function (err, packs) {
+        // console.log 'err', err, 'packs', packs, packs?.length
+        if (err != null) {
+          return callback(err)
+        }
+        if (packs == null) {
+          return callback()
+        }
+        return PackManager.insertPacksIntoIndexWithLock(
+          project_id,
+          doc_id,
+          packs,
+          callback
+        )
       }
-      if (packs == null) {
-        return callback()
-      }
-      return PackManager.insertPacksIntoIndexWithLock(
-        project_id,
-        doc_id,
-        packs,
-        callback
-      )
-    })
+    )
   },
 
   updateIndex(project_id, doc_id, callback) {
     // find all packs prior to current pack
-    return PackManager.findUnindexedPacks(project_id, doc_id, function (
-      err,
-      newPacks
-    ) {
-      if (err != null) {
-        return callback(err)
-      }
-      if (newPacks == null || newPacks.length === 0) {
-        return callback()
-      }
-      return PackManager.insertPacksIntoIndexWithLock(
-        project_id,
-        doc_id,
-        newPacks,
-        function (err) {
-          if (err != null) {
-            return callback(err)
-          }
-          logger.log(
-            { project_id, doc_id, newPacks },
-            'added new packs to index'
-          )
+    return PackManager.findUnindexedPacks(
+      project_id,
+      doc_id,
+      function (err, newPacks) {
+        if (err != null) {
+          return callback(err)
+        }
+        if (newPacks == null || newPacks.length === 0) {
           return callback()
         }
-      )
-    })
+        return PackManager.insertPacksIntoIndexWithLock(
+          project_id,
+          doc_id,
+          newPacks,
+          function (err) {
+            if (err != null) {
+              return callback(err)
+            }
+            logger.log(
+              { project_id, doc_id, newPacks },
+              'added new packs to index'
+            )
+            return callback()
+          }
+        )
+      }
+    )
   },
 
   findCompletedPacks(project_id, doc_id, callback) {
     const query = {
       doc_id: ObjectId(doc_id.toString()),
-      expiresAt: { $exists: false }
+      expiresAt: { $exists: false },
     }
     return db.docHistory
       .find(query, { projection: { pack: false } })
@@ -631,7 +633,7 @@ module.exports = PackManager = {
   findPacks(project_id, doc_id, callback) {
     const query = {
       doc_id: ObjectId(doc_id.toString()),
-      expiresAt: { $exists: false }
+      expiresAt: { $exists: false },
     }
     return db.docHistory
       .find(query, { projection: { pack: false } })
@@ -655,61 +657,63 @@ module.exports = PackManager = {
       if (err != null) {
         return callback(err)
       }
-      return PackManager.findCompletedPacks(project_id, doc_id, function (
-        err,
-        historyPacks
-      ) {
-        let pack
-        if (err != null) {
-          return callback(err)
-        }
-        if (historyPacks == null) {
-          return callback()
-        }
-        // select only the new packs not already in the index
-        let newPacks = (() => {
-          const result = []
-          for (pack of Array.from(historyPacks)) {
-            if (
-              (indexResult != null ? indexResult[pack._id] : undefined) == null
-            ) {
-              result.push(pack)
-            }
+      return PackManager.findCompletedPacks(
+        project_id,
+        doc_id,
+        function (err, historyPacks) {
+          let pack
+          if (err != null) {
+            return callback(err)
           }
-          return result
-        })()
-        newPacks = (() => {
-          const result1 = []
-          for (pack of Array.from(newPacks)) {
-            result1.push(
-              _.omit(
-                pack,
-                'doc_id',
-                'project_id',
-                'n',
-                'sz',
-                'last_checked',
-                'finalised'
+          if (historyPacks == null) {
+            return callback()
+          }
+          // select only the new packs not already in the index
+          let newPacks = (() => {
+            const result = []
+            for (pack of Array.from(historyPacks)) {
+              if (
+                (indexResult != null ? indexResult[pack._id] : undefined) ==
+                null
+              ) {
+                result.push(pack)
+              }
+            }
+            return result
+          })()
+          newPacks = (() => {
+            const result1 = []
+            for (pack of Array.from(newPacks)) {
+              result1.push(
+                _.omit(
+                  pack,
+                  'doc_id',
+                  'project_id',
+                  'n',
+                  'sz',
+                  'last_checked',
+                  'finalised'
+                )
               )
+            }
+            return result1
+          })()
+          if (newPacks.length) {
+            logger.log(
+              { project_id, doc_id, n: newPacks.length },
+              'found new packs'
             )
           }
-          return result1
-        })()
-        if (newPacks.length) {
-          logger.log(
-            { project_id, doc_id, n: newPacks.length },
-            'found new packs'
-          )
+          return callback(null, newPacks)
         }
-        return callback(null, newPacks)
-      })
+      )
     })
   },
 
   insertPacksIntoIndexWithLock(project_id, doc_id, newPacks, callback) {
     return LockManager.runWithLock(
       keys.historyIndexLock({ doc_id }),
-      (releaseLock) =>
+      releaseLock =>
         PackManager._insertPacksIntoIndex(
           project_id,
           doc_id,
@@ -726,11 +730,11 @@ module.exports = PackManager = {
       {
         $setOnInsert: { project_id: ObjectId(project_id.toString()) },
         $push: {
-          packs: { $each: newPacks, $sort: { v: 1 } }
-        }
+          packs: { $each: newPacks, $sort: { v: 1 } },
+        },
       },
       {
-        upsert: true
+        upsert: true,
       },
       callback
     )
@@ -759,36 +763,36 @@ module.exports = PackManager = {
     }
     return async.series(
       [
-        (cb) =>
+        cb =>
           PackManager.checkArchiveNotInProgress(
             project_id,
             doc_id,
             pack_id,
             cb
           ),
-        (cb) =>
+        cb =>
           PackManager.markPackAsArchiveInProgress(
             project_id,
             doc_id,
             pack_id,
             cb
           ),
-        (cb) =>
-          MongoAWS.archivePack(project_id, doc_id, pack_id, (err) =>
+        cb =>
+          MongoAWS.archivePack(project_id, doc_id, pack_id, err =>
             clearFlagOnError(err, cb)
           ),
-        (cb) =>
-          PackManager.checkArchivedPack(project_id, doc_id, pack_id, (err) =>
+        cb =>
+          PackManager.checkArchivedPack(project_id, doc_id, pack_id, err =>
             clearFlagOnError(err, cb)
           ),
-        (cb) => PackManager.markPackAsArchived(project_id, doc_id, pack_id, cb),
-        (cb) =>
+        cb => PackManager.markPackAsArchived(project_id, doc_id, pack_id, cb),
+        cb =>
           PackManager.setTTLOnArchivedPack(
             project_id,
             doc_id,
             pack_id,
             callback
-          )
+          ),
       ],
       callback
     )
@@ -802,40 +806,42 @@ module.exports = PackManager = {
       if (pack == null) {
         return callback(new Error('pack not found'))
       }
-      return MongoAWS.readArchivedPack(project_id, doc_id, pack_id, function (
-        err,
-        result
-      ) {
-        delete result.last_checked
-        delete pack.last_checked
-        // need to compare ids as ObjectIds with .equals()
-        for (const key of ['_id', 'project_id', 'doc_id']) {
-          if (result[key].equals(pack[key])) {
-            result[key] = pack[key]
+      return MongoAWS.readArchivedPack(
+        project_id,
+        doc_id,
+        pack_id,
+        function (err, result) {
+          delete result.last_checked
+          delete pack.last_checked
+          // need to compare ids as ObjectIds with .equals()
+          for (const key of ['_id', 'project_id', 'doc_id']) {
+            if (result[key].equals(pack[key])) {
+              result[key] = pack[key]
+            }
+          }
+          for (let i = 0; i < result.pack.length; i++) {
+            const op = result.pack[i]
+            if (op._id != null && op._id.equals(pack.pack[i]._id)) {
+              op._id = pack.pack[i]._id
+            }
+          }
+          if (_.isEqual(pack, result)) {
+            return callback()
+          } else {
+            logger.err(
+              {
+                pack,
+                result,
+                jsondiff: JSON.stringify(pack) === JSON.stringify(result),
+              },
+              'difference when comparing packs'
+            )
+            return callback(
+              new Error('pack retrieved from s3 does not match pack in mongo')
+            )
           }
         }
-        for (let i = 0; i < result.pack.length; i++) {
-          const op = result.pack[i]
-          if (op._id != null && op._id.equals(pack.pack[i]._id)) {
-            op._id = pack.pack[i]._id
-          }
-        }
-        if (_.isEqual(pack, result)) {
-          return callback()
-        } else {
-          logger.err(
-            {
-              pack,
-              result,
-              jsondiff: JSON.stringify(pack) === JSON.stringify(result)
-            },
-            'difference when comparing packs'
-          )
-          return callback(
-            new Error('pack retrieved from s3 does not match pack in mongo')
-          )
-        }
-      })
+      )
     })
   },
   // Extra methods to test archive/unarchive for a doc_id
@@ -870,15 +876,18 @@ module.exports = PackManager = {
   // Processing old packs via worker
 
   processOldPack(project_id, doc_id, pack_id, callback) {
-    const markAsChecked = (err) =>
-      PackManager.markPackAsChecked(project_id, doc_id, pack_id, function (
-        err2
-      ) {
-        if (err2 != null) {
-          return callback(err2)
+    const markAsChecked = err =>
+      PackManager.markPackAsChecked(
+        project_id,
+        doc_id,
+        pack_id,
+        function (err2) {
+          if (err2 != null) {
+            return callback(err2)
+          }
+          return callback(err)
         }
-        return callback(err)
-      })
+      )
     logger.log({ project_id, doc_id }, 'processing old packs')
     return db.docHistory.findOne({ _id: pack_id }, function (err, pack) {
       if (err != null) {
@@ -899,42 +908,47 @@ module.exports = PackManager = {
           if (err != null) {
             return markAsChecked(err)
           }
-          return PackManager.updateIndexIfNeeded(project_id, doc_id, function (
-            err
-          ) {
-            if (err != null) {
-              return markAsChecked(err)
-            }
-            return PackManager.findUnarchivedPacks(
-              project_id,
-              doc_id,
-              function (err, unarchivedPacks) {
-                if (err != null) {
-                  return markAsChecked(err)
-                }
-                if (
-                  !(unarchivedPacks != null
-                    ? unarchivedPacks.length
-                    : undefined)
-                ) {
-                  logger.log({ project_id, doc_id }, 'no packs need archiving')
-                  return markAsChecked()
-                }
-                return async.eachSeries(
-                  unarchivedPacks,
-                  (pack, cb) =>
-                    PackManager.archivePack(project_id, doc_id, pack._id, cb),
-                  function (err) {
-                    if (err != null) {
-                      return markAsChecked(err)
-                    }
-                    logger.log({ project_id, doc_id }, 'done processing')
+          return PackManager.updateIndexIfNeeded(
+            project_id,
+            doc_id,
+            function (err) {
+              if (err != null) {
+                return markAsChecked(err)
+              }
+              return PackManager.findUnarchivedPacks(
+                project_id,
+                doc_id,
+                function (err, unarchivedPacks) {
+                  if (err != null) {
+                    return markAsChecked(err)
+                  }
+                  if (
+                    !(unarchivedPacks != null
+                      ? unarchivedPacks.length
+                      : undefined)
+                  ) {
+                    logger.log(
+                      { project_id, doc_id },
+                      'no packs need archiving'
+                    )
                     return markAsChecked()
                   }
-                )
-              }
-            )
-          })
+                  return async.eachSeries(
+                    unarchivedPacks,
+                    (pack, cb) =>
+                      PackManager.archivePack(project_id, doc_id, pack._id, cb),
+                    function (err) {
+                      if (err != null) {
+                        return markAsChecked(err)
+                      }
+                      logger.log({ project_id, doc_id }, 'done processing')
+                      return markAsChecked()
+                    }
+                  )
+                }
+              )
+            }
+          )
         }
       )
     })
@@ -974,7 +988,7 @@ module.exports = PackManager = {
   markPackAsFinalisedWithLock(project_id, doc_id, pack_id, callback) {
     return LockManager.runWithLock(
       keys.historyLock({ doc_id }),
-      (releaseLock) =>
+      releaseLock =>
         PackManager._markPackAsFinalised(
           project_id,
           doc_id,
@@ -1050,24 +1064,25 @@ module.exports = PackManager = {
       { project_id, doc_id, pack_id },
       'checking if archive in progress'
     )
-    return PackManager.getPackFromIndex(doc_id, pack_id, function (
-      err,
-      result
-    ) {
-      if (err != null) {
-        return callback(err)
+    return PackManager.getPackFromIndex(
+      doc_id,
+      pack_id,
+      function (err, result) {
+        if (err != null) {
+          return callback(err)
+        }
+        if (result == null) {
+          return callback(new Error('pack not found in index'))
+        }
+        if (result.inS3) {
+          return callback(new Error('pack archiving already done'))
+        } else if (result.inS3 != null) {
+          return callback(new Error('pack archiving already in progress'))
+        } else {
+          return callback()
+        }
       }
-      if (result == null) {
-        return callback(new Error('pack not found in index'))
-      }
-      if (result.inS3) {
-        return callback(new Error('pack archiving already done'))
-      } else if (result.inS3 != null) {
-        return callback(new Error('pack archiving already in progress'))
-      } else {
-        return callback()
-      }
-    })
+    )
   },
 
   markPackAsArchiveInProgress(project_id, doc_id, pack_id, callback) {
@@ -1078,7 +1093,7 @@ module.exports = PackManager = {
     return db.docHistoryIndex.findOneAndUpdate(
       {
         _id: ObjectId(doc_id.toString()),
-        packs: { $elemMatch: { _id: pack_id, inS3: { $exists: false } } }
+        packs: { $elemMatch: { _id: pack_id, inS3: { $exists: false } } },
       },
       { $set: { 'packs.$.inS3': false } },
       { projection: { 'packs.$': 1 } },
@@ -1106,7 +1121,7 @@ module.exports = PackManager = {
     return db.docHistoryIndex.updateOne(
       {
         _id: ObjectId(doc_id.toString()),
-        packs: { $elemMatch: { _id: pack_id, inS3: false } }
+        packs: { $elemMatch: { _id: pack_id, inS3: false } },
       },
       { $unset: { 'packs.$.inS3': true } },
       callback
@@ -1118,7 +1133,7 @@ module.exports = PackManager = {
     return db.docHistoryIndex.findOneAndUpdate(
       {
         _id: ObjectId(doc_id.toString()),
-        packs: { $elemMatch: { _id: pack_id, inS3: false } }
+        packs: { $elemMatch: { _id: pack_id, inS3: false } },
       },
       { $set: { 'packs.$.inS3': true } },
       { projection: { 'packs.$': 1 } },
@@ -1147,7 +1162,7 @@ module.exports = PackManager = {
         return callback()
       }
     )
-  }
+  },
 }
 
 //	_getOneDayInFutureWithRandomDelay: ->
diff --git a/services/track-changes/app/js/PackWorker.js b/services/track-changes/app/js/PackWorker.js
index fe507fe815..38e99101de 100644
--- a/services/track-changes/app/js/PackWorker.js
+++ b/services/track-changes/app/js/PackWorker.js
@@ -53,8 +53,8 @@ if (!source.match(/^[0-9]+$/)) {
     }
     return result1
   })()
-  pending = _.filter(result, (row) =>
-    __guard__(row != null ? row.doc_id : undefined, (x) =>
+  pending = _.filter(result, row =>
+    __guard__(row != null ? row.doc_id : undefined, x =>
       x.match(/^[a-f0-9]{24}$/)
     )
   )
@@ -101,9 +101,9 @@ const finish = function () {
   })
 }
 
-process.on('exit', (code) => logger.log({ code }, 'pack archive worker exited'))
+process.on('exit', code => logger.log({ code }, 'pack archive worker exited'))
 
-const processUpdates = (pending) =>
+const processUpdates = pending =>
   async.eachSeries(
     pending,
     function (result, callback) {
@@ -170,7 +170,7 @@ waitForDb()
       processFromOneWeekAgo()
     }
   })
-  .catch((err) => {
+  .catch(err => {
     logger.fatal({ err }, 'cannot connect to mongo, exiting')
     process.exit(1)
   })
@@ -184,12 +184,12 @@ function processFromOneWeekAgo() {
         project_id: { $exists: true },
         v_end: { $exists: true },
         _id: { $lt: ObjectIdFromDate(oneWeekAgo) },
-        last_checked: { $lt: oneWeekAgo }
+        last_checked: { $lt: oneWeekAgo },
       },
       { projection: { _id: 1, doc_id: 1, project_id: 1 } }
     )
     .sort({
-      last_checked: 1
+      last_checked: 1,
     })
     .limit(LIMIT)
     .toArray(function (err, results) {
@@ -198,7 +198,7 @@ function processFromOneWeekAgo() {
         finish()
         return
       }
-      pending = _.uniq(results, false, (result) => result.doc_id.toString())
+      pending = _.uniq(results, false, result => result.doc_id.toString())
       TOTAL = pending.length
       logger.log(`found ${TOTAL} documents to archive`)
       return processUpdates(pending)
diff --git a/services/track-changes/app/js/ProjectIterator.js b/services/track-changes/app/js/ProjectIterator.js
index 43ddbc7b2f..2b9da401b3 100644
--- a/services/track-changes/app/js/ProjectIterator.js
+++ b/services/track-changes/app/js/ProjectIterator.js
@@ -14,96 +14,100 @@
 let ProjectIterator
 const Heap = require('heap')
 
-module.exports = ProjectIterator = ProjectIterator = class ProjectIterator {
-  constructor(packs, before, getPackByIdFn) {
-    this.before = before
-    this.getPackByIdFn = getPackByIdFn
-    const byEndTs = (a, b) =>
-      b.meta.end_ts - a.meta.end_ts || a.fromIndex - b.fromIndex
-    this.packs = packs.slice().sort(byEndTs)
-    this.queue = new Heap(byEndTs)
-  }
+module.exports =
+  ProjectIterator =
+  ProjectIterator =
+    class ProjectIterator {
+      constructor(packs, before, getPackByIdFn) {
+        this.before = before
+        this.getPackByIdFn = getPackByIdFn
+        const byEndTs = (a, b) =>
+          b.meta.end_ts - a.meta.end_ts || a.fromIndex - b.fromIndex
+        this.packs = packs.slice().sort(byEndTs)
+        this.queue = new Heap(byEndTs)
+      }
 
-  next(callback) {
-    //  what's up next
-    // console.log ">>> top item", iterator.packs[0]
-    const iterator = this
-    const { before } = this
-    const { queue } = iterator
-    const opsToReturn = []
-    let nextPack = iterator.packs[0]
-    let lowWaterMark =
-      (nextPack != null ? nextPack.meta.end_ts : undefined) || 0
-    let nextItem = queue.peek()
+      next(callback) {
+        //  what's up next
+        // console.log ">>> top item", iterator.packs[0]
+        const iterator = this
+        const { before } = this
+        const { queue } = iterator
+        const opsToReturn = []
+        let nextPack = iterator.packs[0]
+        let lowWaterMark =
+          (nextPack != null ? nextPack.meta.end_ts : undefined) || 0
+        let nextItem = queue.peek()
 
-    // console.log "queue empty?", queue.empty()
-    // console.log "nextItem", nextItem
-    // console.log "nextItem.meta.end_ts", nextItem?.meta.end_ts
-    // console.log "lowWaterMark", lowWaterMark
+        // console.log "queue empty?", queue.empty()
+        // console.log "nextItem", nextItem
+        // console.log "nextItem.meta.end_ts", nextItem?.meta.end_ts
+        // console.log "lowWaterMark", lowWaterMark
 
-    while (
-      before != null &&
-      (nextPack != null ? nextPack.meta.start_ts : undefined) > before
-    ) {
-      // discard pack that is outside range
-      iterator.packs.shift()
-      nextPack = iterator.packs[0]
-      lowWaterMark = (nextPack != null ? nextPack.meta.end_ts : undefined) || 0
-    }
-
-    if (
-      (queue.empty() ||
-        (nextItem != null ? nextItem.meta.end_ts : undefined) <=
-          lowWaterMark) &&
-      nextPack != null
-    ) {
-      // retrieve the next pack and populate the queue
-      return this.getPackByIdFn(
-        nextPack.project_id,
-        nextPack.doc_id,
-        nextPack._id,
-        function (err, pack) {
-          if (err != null) {
-            return callback(err)
-          }
-          iterator.packs.shift() // have now retrieved this pack, remove it
-          // console.log "got pack", pack
-          for (const op of Array.from(pack.pack)) {
-            // console.log "adding op", op
-            if (before == null || op.meta.end_ts < before) {
-              op.doc_id = nextPack.doc_id
-              op.project_id = nextPack.project_id
-              queue.push(op)
-            }
-          }
-          // now try again
-          return iterator.next(callback)
+        while (
+          before != null &&
+          (nextPack != null ? nextPack.meta.start_ts : undefined) > before
+        ) {
+          // discard pack that is outside range
+          iterator.packs.shift()
+          nextPack = iterator.packs[0]
+          lowWaterMark =
+            (nextPack != null ? nextPack.meta.end_ts : undefined) || 0
         }
-      )
+
+        if (
+          (queue.empty() ||
+            (nextItem != null ? nextItem.meta.end_ts : undefined) <=
+              lowWaterMark) &&
+          nextPack != null
+        ) {
+          // retrieve the next pack and populate the queue
+          return this.getPackByIdFn(
+            nextPack.project_id,
+            nextPack.doc_id,
+            nextPack._id,
+            function (err, pack) {
+              if (err != null) {
+                return callback(err)
+              }
+              iterator.packs.shift() // have now retrieved this pack, remove it
+              // console.log "got pack", pack
+              for (const op of Array.from(pack.pack)) {
+                // console.log "adding op", op
+                if (before == null || op.meta.end_ts < before) {
+                  op.doc_id = nextPack.doc_id
+                  op.project_id = nextPack.project_id
+                  queue.push(op)
+                }
+              }
+              // now try again
+              return iterator.next(callback)
+            }
+          )
+        }
+
+        // console.log "nextItem", nextItem, "lowWaterMark", lowWaterMark
+        while (
+          nextItem != null &&
+          (nextItem != null ? nextItem.meta.end_ts : undefined) > lowWaterMark
+        ) {
+          opsToReturn.push(nextItem)
+          queue.pop()
+          nextItem = queue.peek()
+        }
+
+        // console.log "queue empty?", queue.empty()
+        // console.log "nextPack", nextPack?
+
+        if (queue.empty() && nextPack == null) {
+          // got everything
+          iterator._done = true
+        }
+
+        return callback(null, opsToReturn)
+      }
+
+      done() {
+        return this._done
+      }
     }
-
-    // console.log "nextItem", nextItem, "lowWaterMark", lowWaterMark
-    while (
-      nextItem != null &&
-      (nextItem != null ? nextItem.meta.end_ts : undefined) > lowWaterMark
-    ) {
-      opsToReturn.push(nextItem)
-      queue.pop()
-      nextItem = queue.peek()
-    }
-
-    // console.log "queue empty?", queue.empty()
-    // console.log "nextPack", nextPack?
-
-    if (queue.empty() && nextPack == null) {
-      // got everything
-      iterator._done = true
-    }
-
-    return callback(null, opsToReturn)
-  }
-
-  done() {
-    return this._done
-  }
-}
diff --git a/services/track-changes/app/js/RedisManager.js b/services/track-changes/app/js/RedisManager.js
index 6a88c31303..4998c4757f 100644
--- a/services/track-changes/app/js/RedisManager.js
+++ b/services/track-changes/app/js/RedisManager.js
@@ -34,7 +34,7 @@ module.exports = RedisManager = {
       callback = function (error, rawUpdates) {}
     }
     try {
-      rawUpdates = Array.from(jsonUpdates || []).map((update) =>
+      rawUpdates = Array.from(jsonUpdates || []).map(update =>
         JSON.parse(update)
       )
     } catch (e) {
@@ -93,26 +93,30 @@ module.exports = RedisManager = {
     let cursor = 0 // redis iterator
     const keySet = {} // use hash to avoid duplicate results
     // scan over all keys looking for pattern
-    var doIteration = (cb) =>
-      node.scan(cursor, 'MATCH', pattern, 'COUNT', 1000, function (
-        error,
-        reply
-      ) {
-        let keys
-        if (error != null) {
-          return callback(error)
+    var doIteration = cb =>
+      node.scan(
+        cursor,
+        'MATCH',
+        pattern,
+        'COUNT',
+        1000,
+        function (error, reply) {
+          let keys
+          if (error != null) {
+            return callback(error)
+          }
+          ;[cursor, keys] = Array.from(reply)
+          for (const key of Array.from(keys)) {
+            keySet[key] = true
+          }
+          if (cursor === '0') {
+            // note redis returns string result not numeric
+            return callback(null, Object.keys(keySet))
+          } else {
+            return doIteration()
+          }
         }
-        ;[cursor, keys] = Array.from(reply)
-        for (const key of Array.from(keys)) {
-          keySet[key] = true
-        }
-        if (cursor === '0') {
-          // note redis returns string result not numeric
-          return callback(null, Object.keys(keySet))
-        } else {
-          return doIteration()
-        }
-      })
+      )
     return doIteration()
   },
 
@@ -162,5 +166,5 @@ module.exports = RedisManager = {
         return callback(error, doc_ids)
       }
     )
-  }
+  },
 }
diff --git a/services/track-changes/app/js/RestoreManager.js b/services/track-changes/app/js/RestoreManager.js
index 6a1af1af44..84ddaf5236 100644
--- a/services/track-changes/app/js/RestoreManager.js
+++ b/services/track-changes/app/js/RestoreManager.js
@@ -44,5 +44,5 @@ module.exports = RestoreManager = {
         )
       }
     )
-  }
+  },
 }
diff --git a/services/track-changes/app/js/UpdateCompressor.js b/services/track-changes/app/js/UpdateCompressor.js
index 019ad32760..8e447f95c0 100644
--- a/services/track-changes/app/js/UpdateCompressor.js
+++ b/services/track-changes/app/js/UpdateCompressor.js
@@ -42,16 +42,16 @@ module.exports = UpdateCompressor = {
     const splitUpdates = []
     for (const update of Array.from(updates)) {
       // Reject any non-insert or delete ops, i.e. comments
-      const ops = update.op.filter((o) => o.i != null || o.d != null)
+      const ops = update.op.filter(o => o.i != null || o.d != null)
       if (ops.length === 0) {
         splitUpdates.push({
           op: UpdateCompressor.NOOP,
           meta: {
             start_ts: update.meta.start_ts || update.meta.ts,
             end_ts: update.meta.end_ts || update.meta.ts,
-            user_id: update.meta.user_id
+            user_id: update.meta.user_id,
           },
-          v: update.v
+          v: update.v,
         })
       } else {
         for (const op of Array.from(ops)) {
@@ -60,9 +60,9 @@ module.exports = UpdateCompressor = {
             meta: {
               start_ts: update.meta.start_ts || update.meta.ts,
               end_ts: update.meta.end_ts || update.meta.ts,
-              user_id: update.meta.user_id
+              user_id: update.meta.user_id,
             },
-            v: update.v
+            v: update.v,
           })
         }
       }
@@ -82,7 +82,7 @@ module.exports = UpdateCompressor = {
         const nextUpdate = {
           op: [],
           meta: update.meta,
-          v: update.v
+          v: update.v,
         }
         if (update.op !== UpdateCompressor.NOOP) {
           nextUpdate.op.push(update.op)
@@ -97,7 +97,7 @@ module.exports = UpdateCompressor = {
     if (
       __guard__(
         lastPreviousUpdate != null ? lastPreviousUpdate.op : undefined,
-        (x) => x.length
+        x => x.length
       ) > 1
     ) {
       // if the last previous update was an array op, don't compress onto it.
@@ -144,18 +144,18 @@ module.exports = UpdateCompressor = {
       meta: {
         user_id: firstUpdate.meta.user_id || null,
         start_ts: firstUpdate.meta.start_ts || firstUpdate.meta.ts,
-        end_ts: firstUpdate.meta.end_ts || firstUpdate.meta.ts
+        end_ts: firstUpdate.meta.end_ts || firstUpdate.meta.ts,
       },
-      v: firstUpdate.v
+      v: firstUpdate.v,
     }
     secondUpdate = {
       op: secondUpdate.op,
       meta: {
         user_id: secondUpdate.meta.user_id || null,
         start_ts: secondUpdate.meta.start_ts || secondUpdate.meta.ts,
-        end_ts: secondUpdate.meta.end_ts || secondUpdate.meta.ts
+        end_ts: secondUpdate.meta.end_ts || secondUpdate.meta.ts,
       },
-      v: secondUpdate.v
+      v: secondUpdate.v,
     }
 
     if (firstUpdate.meta.user_id !== secondUpdate.meta.user_id) {
@@ -192,14 +192,14 @@ module.exports = UpdateCompressor = {
           meta: {
             start_ts: firstUpdate.meta.start_ts,
             end_ts: secondUpdate.meta.end_ts,
-            user_id: firstUpdate.meta.user_id
+            user_id: firstUpdate.meta.user_id,
           },
           op: {
             p: firstOp.p,
-            i: strInject(firstOp.i, secondOp.p - firstOp.p, secondOp.i)
+            i: strInject(firstOp.i, secondOp.p - firstOp.p, secondOp.i),
           },
-          v: secondUpdate.v
-        }
+          v: secondUpdate.v,
+        },
       ]
       // Two deletes
     } else if (
@@ -214,14 +214,14 @@ module.exports = UpdateCompressor = {
           meta: {
             start_ts: firstUpdate.meta.start_ts,
             end_ts: secondUpdate.meta.end_ts,
-            user_id: firstUpdate.meta.user_id
+            user_id: firstUpdate.meta.user_id,
           },
           op: {
             p: secondOp.p,
-            d: strInject(secondOp.d, firstOp.p - secondOp.p, firstOp.d)
+            d: strInject(secondOp.d, firstOp.p - secondOp.p, firstOp.d),
           },
-          v: secondUpdate.v
-        }
+          v: secondUpdate.v,
+        },
       ]
       // An insert and then a delete
     } else if (
@@ -240,14 +240,14 @@ module.exports = UpdateCompressor = {
             meta: {
               start_ts: firstUpdate.meta.start_ts,
               end_ts: secondUpdate.meta.end_ts,
-              user_id: firstUpdate.meta.user_id
+              user_id: firstUpdate.meta.user_id,
             },
             op: {
               p: firstOp.p,
-              i: insert
+              i: insert,
             },
-            v: secondUpdate.v
-          }
+            v: secondUpdate.v,
+          },
         ]
       } else {
         // This will only happen if the delete extends outside the insert
@@ -269,14 +269,14 @@ module.exports = UpdateCompressor = {
             meta: {
               start_ts: firstUpdate.meta.start_ts,
               end_ts: secondUpdate.meta.end_ts,
-              user_id: firstUpdate.meta.user_id
+              user_id: firstUpdate.meta.user_id,
             },
             op: {
               p: firstOp.p,
-              i: ''
+              i: '',
             },
-            v: secondUpdate.v
-          }
+            v: secondUpdate.v,
+          },
         ]
       } else {
         return diff_ops.map(function (op) {
@@ -285,10 +285,10 @@ module.exports = UpdateCompressor = {
             meta: {
               start_ts: firstUpdate.meta.start_ts,
               end_ts: secondUpdate.meta.end_ts,
-              user_id: firstUpdate.meta.user_id
+              user_id: firstUpdate.meta.user_id,
             },
             op,
-            v: secondUpdate.v
+            v: secondUpdate.v,
           }
         })
       }
@@ -315,13 +315,13 @@ module.exports = UpdateCompressor = {
       if (type === this.ADDED) {
         ops.push({
           i: content,
-          p: position
+          p: position,
         })
         position += content.length
       } else if (type === this.REMOVED) {
         ops.push({
           d: content,
-          p: position
+          p: position,
         })
       } else if (type === this.UNCHANGED) {
         position += content.length
@@ -330,7 +330,7 @@ module.exports = UpdateCompressor = {
       }
     }
     return ops
-  }
+  },
 }
 
 function __guard__(value, transform) {
diff --git a/services/track-changes/app/js/UpdateTrimmer.js b/services/track-changes/app/js/UpdateTrimmer.js
index 5fabe1cb9e..b37bf545f2 100644
--- a/services/track-changes/app/js/UpdateTrimmer.js
+++ b/services/track-changes/app/js/UpdateTrimmer.js
@@ -22,54 +22,55 @@ module.exports = UpdateTrimmer = {
     if (callback == null) {
       callback = function (error, shouldTrim) {}
     }
-    return MongoManager.getProjectMetaData(project_id, function (
-      error,
-      metadata
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      if (metadata != null ? metadata.preserveHistory : undefined) {
-        return callback(null, false)
-      } else {
-        return WebApiManager.getProjectDetails(project_id, function (
-          error,
-          details
-        ) {
-          if (error != null) {
-            return callback(error)
-          }
-          logger.log({ project_id, details }, 'got details')
-          if (
-            __guard__(
-              details != null ? details.features : undefined,
-              (x) => x.versioning
-            )
-          ) {
-            return MongoManager.setProjectMetaData(
-              project_id,
-              { preserveHistory: true },
-              function (error) {
-                if (error != null) {
-                  return callback(error)
-                }
-                return MongoManager.upgradeHistory(project_id, function (
-                  error
-                ) {
-                  if (error != null) {
-                    return callback(error)
-                  }
-                  return callback(null, false)
-                })
+    return MongoManager.getProjectMetaData(
+      project_id,
+      function (error, metadata) {
+        if (error != null) {
+          return callback(error)
+        }
+        if (metadata != null ? metadata.preserveHistory : undefined) {
+          return callback(null, false)
+        } else {
+          return WebApiManager.getProjectDetails(
+            project_id,
+            function (error, details) {
+              if (error != null) {
+                return callback(error)
               }
-            )
-          } else {
-            return callback(null, true)
-          }
-        })
+              logger.log({ project_id, details }, 'got details')
+              if (
+                __guard__(
+                  details != null ? details.features : undefined,
+                  x => x.versioning
+                )
+              ) {
+                return MongoManager.setProjectMetaData(
+                  project_id,
+                  { preserveHistory: true },
+                  function (error) {
+                    if (error != null) {
+                      return callback(error)
+                    }
+                    return MongoManager.upgradeHistory(
+                      project_id,
+                      function (error) {
+                        if (error != null) {
+                          return callback(error)
+                        }
+                        return callback(null, false)
+                      }
+                    )
+                  }
+                )
+              } else {
+                return callback(null, true)
+              }
+            }
+          )
+        }
       }
-    })
-  }
+    )
+  },
 }
 
 function __guard__(value, transform) {
diff --git a/services/track-changes/app/js/UpdatesManager.js b/services/track-changes/app/js/UpdatesManager.js
index 2acdf8039d..26c1104569 100644
--- a/services/track-changes/app/js/UpdatesManager.js
+++ b/services/track-changes/app/js/UpdatesManager.js
@@ -50,7 +50,7 @@ module.exports = UpdatesManager = {
       const op = rawUpdates[i]
       if (i > 0) {
         const thisVersion = op != null ? op.v : undefined
-        const prevVersion = __guard__(rawUpdates[i - 1], (x) => x.v)
+        const prevVersion = __guard__(rawUpdates[i - 1], x => x.v)
         if (!(prevVersion < thisVersion)) {
           logger.error(
             {
@@ -59,7 +59,7 @@ module.exports = UpdatesManager = {
               rawUpdates,
               temporary,
               thisVersion,
-              prevVersion
+              prevVersion,
             },
             'op versions out of order'
           )
@@ -69,138 +69,137 @@ module.exports = UpdatesManager = {
 
     // FIXME: we no longer need the lastCompressedUpdate, so change functions not to need it
     // CORRECTION:  we do use it to log the time in case of error
-    return MongoManager.peekLastCompressedUpdate(doc_id, function (
-      error,
-      lastCompressedUpdate,
-      lastVersion
-    ) {
-      // lastCompressedUpdate is the most recent update in Mongo, and
-      // lastVersion is its sharejs version number.
-      //
-      // The peekLastCompressedUpdate method may pass the update back
-      // as 'null' (for example if the previous compressed update has
-      // been archived).  In this case it can still pass back the
-      // lastVersion from the update to allow us to check consistency.
-      let op
-      if (error != null) {
-        return callback(error)
-      }
-
-      // Ensure that raw updates start where lastVersion left off
-      if (lastVersion != null) {
-        const discardedUpdates = []
-        rawUpdates = rawUpdates.slice(0)
-        while (rawUpdates[0] != null && rawUpdates[0].v <= lastVersion) {
-          discardedUpdates.push(rawUpdates.shift())
-        }
-        if (discardedUpdates.length) {
-          logger.error(
-            { project_id, doc_id, discardedUpdates, temporary, lastVersion },
-            'discarded updates already present'
-          )
+    return MongoManager.peekLastCompressedUpdate(
+      doc_id,
+      function (error, lastCompressedUpdate, lastVersion) {
+        // lastCompressedUpdate is the most recent update in Mongo, and
+        // lastVersion is its sharejs version number.
+        //
+        // The peekLastCompressedUpdate method may pass the update back
+        // as 'null' (for example if the previous compressed update has
+        // been archived).  In this case it can still pass back the
+        // lastVersion from the update to allow us to check consistency.
+        let op
+        if (error != null) {
+          return callback(error)
         }
 
-        if (rawUpdates[0] != null && rawUpdates[0].v !== lastVersion + 1) {
-          const ts = __guard__(
-            lastCompressedUpdate != null
-              ? lastCompressedUpdate.meta
-              : undefined,
-            (x1) => x1.end_ts
-          )
-          const last_timestamp = ts != null ? new Date(ts) : 'unknown time'
-          error = new Error(
-            `Tried to apply raw op at version ${rawUpdates[0].v} to last compressed update with version ${lastVersion} from ${last_timestamp}`
-          )
-          logger.error(
-            {
-              err: error,
-              doc_id,
-              project_id,
-              prev_end_ts: ts,
-              temporary,
-              lastCompressedUpdate
-            },
-            'inconsistent doc versions'
-          )
-          if (
-            (Settings.trackchanges != null
-              ? Settings.trackchanges.continueOnError
-              : undefined) &&
-            rawUpdates[0].v > lastVersion + 1
-          ) {
-            // we have lost some ops - continue to write into the database, we can't recover at this point
-            lastCompressedUpdate = null
-          } else {
-            return callback(error)
+        // Ensure that raw updates start where lastVersion left off
+        if (lastVersion != null) {
+          const discardedUpdates = []
+          rawUpdates = rawUpdates.slice(0)
+          while (rawUpdates[0] != null && rawUpdates[0].v <= lastVersion) {
+            discardedUpdates.push(rawUpdates.shift())
           }
-        }
-      }
-
-      if (rawUpdates.length === 0) {
-        return callback()
-      }
-
-      // some old large ops in redis need to be rejected, they predate
-      // the size limit that now prevents them going through the system
-      const REJECT_LARGE_OP_SIZE = 4 * 1024 * 1024
-      for (var rawUpdate of Array.from(rawUpdates)) {
-        const opSizes = (() => {
-          const result = []
-          for (op of Array.from(
-            (rawUpdate != null ? rawUpdate.op : undefined) || []
-          )) {
-            result.push(
-              (op.i != null ? op.i.length : undefined) ||
-                (op.d != null ? op.d.length : undefined)
+          if (discardedUpdates.length) {
+            logger.error(
+              { project_id, doc_id, discardedUpdates, temporary, lastVersion },
+              'discarded updates already present'
             )
           }
-          return result
-        })()
-        const size = _.max(opSizes)
-        if (size > REJECT_LARGE_OP_SIZE) {
-          error = new Error(
-            `dropped op exceeding maximum allowed size of ${REJECT_LARGE_OP_SIZE}`
-          )
-          logger.error(
-            { err: error, doc_id, project_id, size, rawUpdate },
-            'dropped op - too big'
-          )
-          rawUpdate.op = []
-        }
-      }
 
-      const compressedUpdates = UpdateCompressor.compressRawUpdates(
-        null,
-        rawUpdates
-      )
-      return PackManager.insertCompressedUpdates(
-        project_id,
-        doc_id,
-        lastCompressedUpdate,
-        compressedUpdates,
-        temporary,
-        function (error, result) {
-          if (error != null) {
-            return callback(error)
-          }
-          if (result != null) {
-            logger.log(
+          if (rawUpdates[0] != null && rawUpdates[0].v !== lastVersion + 1) {
+            const ts = __guard__(
+              lastCompressedUpdate != null
+                ? lastCompressedUpdate.meta
+                : undefined,
+              x1 => x1.end_ts
+            )
+            const last_timestamp = ts != null ? new Date(ts) : 'unknown time'
+            error = new Error(
+              `Tried to apply raw op at version ${rawUpdates[0].v} to last compressed update with version ${lastVersion} from ${last_timestamp}`
+            )
+            logger.error(
               {
-                project_id,
+                err: error,
                 doc_id,
-                orig_v:
-                  lastCompressedUpdate != null
-                    ? lastCompressedUpdate.v
-                    : undefined,
-                new_v: result.v
+                project_id,
+                prev_end_ts: ts,
+                temporary,
+                lastCompressedUpdate,
               },
-              'inserted updates into pack'
+              'inconsistent doc versions'
             )
+            if (
+              (Settings.trackchanges != null
+                ? Settings.trackchanges.continueOnError
+                : undefined) &&
+              rawUpdates[0].v > lastVersion + 1
+            ) {
+              // we have lost some ops - continue to write into the database, we can't recover at this point
+              lastCompressedUpdate = null
+            } else {
+              return callback(error)
+            }
           }
+        }
+
+        if (rawUpdates.length === 0) {
           return callback()
         }
-      )
-    })
+
+        // some old large ops in redis need to be rejected, they predate
+        // the size limit that now prevents them going through the system
+        const REJECT_LARGE_OP_SIZE = 4 * 1024 * 1024
+        for (var rawUpdate of Array.from(rawUpdates)) {
+          const opSizes = (() => {
+            const result = []
+            for (op of Array.from(
+              (rawUpdate != null ? rawUpdate.op : undefined) || []
+            )) {
+              result.push(
+                (op.i != null ? op.i.length : undefined) ||
+                  (op.d != null ? op.d.length : undefined)
+              )
+            }
+            return result
+          })()
+          const size = _.max(opSizes)
+          if (size > REJECT_LARGE_OP_SIZE) {
+            error = new Error(
+              `dropped op exceeding maximum allowed size of ${REJECT_LARGE_OP_SIZE}`
+            )
+            logger.error(
+              { err: error, doc_id, project_id, size, rawUpdate },
+              'dropped op - too big'
+            )
+            rawUpdate.op = []
+          }
+        }
+
+        const compressedUpdates = UpdateCompressor.compressRawUpdates(
+          null,
+          rawUpdates
+        )
+        return PackManager.insertCompressedUpdates(
+          project_id,
+          doc_id,
+          lastCompressedUpdate,
+          compressedUpdates,
+          temporary,
+          function (error, result) {
+            if (error != null) {
+              return callback(error)
+            }
+            if (result != null) {
+              logger.log(
+                {
+                  project_id,
+                  doc_id,
+                  orig_v:
+                    lastCompressedUpdate != null
+                      ? lastCompressedUpdate.v
+                      : undefined,
+                  new_v: result.v,
+                },
+                'inserted updates into pack'
+              )
+            }
+            return callback()
+          }
+        )
+      }
+    )
   },
 
   // Check whether the updates are temporary (per-project property)
@@ -208,15 +207,15 @@ module.exports = UpdatesManager = {
     if (callback == null) {
       callback = function (error, temporary) {}
     }
-    return UpdateTrimmer.shouldTrimUpdates(project_id, function (
-      error,
-      temporary
-    ) {
-      if (error != null) {
-        return callback(error)
+    return UpdateTrimmer.shouldTrimUpdates(
+      project_id,
+      function (error, temporary) {
+        if (error != null) {
+          return callback(error)
+        }
+        return callback(null, temporary)
       }
-      return callback(null, temporary)
-    })
+    )
   },
 
   // Check for project id on document history (per-document property)
@@ -248,71 +247,71 @@ module.exports = UpdatesManager = {
         }
         const { length } = docUpdates
         // parse the redis strings into ShareJs updates
-        return RedisManager.expandDocUpdates(docUpdates, function (
-          error,
-          rawUpdates
-        ) {
-          if (error != null) {
-            logger.err(
-              { project_id, doc_id, docUpdates },
-              'failed to parse docUpdates'
-            )
-            return callback(error)
-          }
-          logger.log(
-            { project_id, doc_id, rawUpdates },
-            'retrieved raw updates from redis'
-          )
-          return UpdatesManager.compressAndSaveRawUpdates(
-            project_id,
-            doc_id,
-            rawUpdates,
-            temporary,
-            function (error) {
-              if (error != null) {
-                return callback(error)
-              }
-              logger.log(
-                { project_id, doc_id },
-                'compressed and saved doc updates'
-              )
-              // delete the applied updates from redis
-              return RedisManager.deleteAppliedDocUpdates(
-                project_id,
-                doc_id,
-                docUpdates,
-                function (error) {
-                  if (error != null) {
-                    return callback(error)
-                  }
-                  if (length === UpdatesManager.REDIS_READ_BATCH_SIZE) {
-                    // There might be more updates
-                    logger.log(
-                      { project_id, doc_id },
-                      'continuing processing updates'
-                    )
-                    return setTimeout(
-                      () =>
-                        UpdatesManager.processUncompressedUpdates(
-                          project_id,
-                          doc_id,
-                          temporary,
-                          callback
-                        ),
-                      0
-                    )
-                  } else {
-                    logger.log(
-                      { project_id, doc_id },
-                      'all raw updates processed'
-                    )
-                    return callback()
-                  }
-                }
+        return RedisManager.expandDocUpdates(
+          docUpdates,
+          function (error, rawUpdates) {
+            if (error != null) {
+              logger.err(
+                { project_id, doc_id, docUpdates },
+                'failed to parse docUpdates'
               )
+              return callback(error)
             }
-          )
-        })
+            logger.log(
+              { project_id, doc_id, rawUpdates },
+              'retrieved raw updates from redis'
+            )
+            return UpdatesManager.compressAndSaveRawUpdates(
+              project_id,
+              doc_id,
+              rawUpdates,
+              temporary,
+              function (error) {
+                if (error != null) {
+                  return callback(error)
+                }
+                logger.log(
+                  { project_id, doc_id },
+                  'compressed and saved doc updates'
+                )
+                // delete the applied updates from redis
+                return RedisManager.deleteAppliedDocUpdates(
+                  project_id,
+                  doc_id,
+                  docUpdates,
+                  function (error) {
+                    if (error != null) {
+                      return callback(error)
+                    }
+                    if (length === UpdatesManager.REDIS_READ_BATCH_SIZE) {
+                      // There might be more updates
+                      logger.log(
+                        { project_id, doc_id },
+                        'continuing processing updates'
+                      )
+                      return setTimeout(
+                        () =>
+                          UpdatesManager.processUncompressedUpdates(
+                            project_id,
+                            doc_id,
+                            temporary,
+                            callback
+                          ),
+                        0
+                      )
+                    } else {
+                      logger.log(
+                        { project_id, doc_id },
+                        'all raw updates processed'
+                      )
+                      return callback()
+                    }
+                  }
+                )
+              }
+            )
+          }
+        )
       }
     )
   },
@@ -322,20 +321,20 @@ module.exports = UpdatesManager = {
     if (callback == null) {
       callback = function (error) {}
     }
-    return UpdatesManager._prepareProjectForUpdates(project_id, function (
-      error,
-      temporary
-    ) {
-      if (error != null) {
-        return callback(error)
+    return UpdatesManager._prepareProjectForUpdates(
+      project_id,
+      function (error, temporary) {
+        if (error != null) {
+          return callback(error)
+        }
+        return UpdatesManager._processUncompressedUpdatesForDocWithLock(
+          project_id,
+          doc_id,
+          temporary,
+          callback
+        )
       }
-      return UpdatesManager._processUncompressedUpdatesForDocWithLock(
-        project_id,
-        doc_id,
-        temporary,
-        callback
-      )
-    })
+    )
   },
 
   // Process updates for a doc when the whole project is flushed (internal method)
@@ -348,24 +347,26 @@ module.exports = UpdatesManager = {
     if (callback == null) {
       callback = function (error) {}
     }
-    return UpdatesManager._prepareDocForUpdates(project_id, doc_id, function (
-      error
-    ) {
-      if (error != null) {
-        return callback(error)
+    return UpdatesManager._prepareDocForUpdates(
+      project_id,
+      doc_id,
+      function (error) {
+        if (error != null) {
+          return callback(error)
+        }
+        return LockManager.runWithLock(
+          keys.historyLock({ doc_id }),
+          releaseLock =>
+            UpdatesManager.processUncompressedUpdates(
+              project_id,
+              doc_id,
+              temporary,
+              releaseLock
+            ),
+          callback
+        )
       }
-      return LockManager.runWithLock(
-        keys.historyLock({ doc_id }),
-        (releaseLock) =>
-          UpdatesManager.processUncompressedUpdates(
-            project_id,
-            doc_id,
-            temporary,
-            releaseLock
-          ),
-        callback
-      )
-    })
+    )
   },
 
   // Process all updates for a project, only check project-level information once
@@ -373,32 +374,32 @@ module.exports = UpdatesManager = {
     if (callback == null) {
       callback = function (error) {}
     }
-    return RedisManager.getDocIdsWithHistoryOps(project_id, function (
-      error,
-      doc_ids
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      return UpdatesManager._prepareProjectForUpdates(project_id, function (
-        error,
-        temporary
-      ) {
-        const jobs = []
-        for (const doc_id of Array.from(doc_ids)) {
-          ;((doc_id) =>
-            jobs.push((cb) =>
-              UpdatesManager._processUncompressedUpdatesForDocWithLock(
-                project_id,
-                doc_id,
-                temporary,
-                cb
-              )
-            ))(doc_id)
+    return RedisManager.getDocIdsWithHistoryOps(
+      project_id,
+      function (error, doc_ids) {
+        if (error != null) {
+          return callback(error)
         }
-        return async.parallelLimit(jobs, 5, callback)
-      })
-    })
+        return UpdatesManager._prepareProjectForUpdates(
+          project_id,
+          function (error, temporary) {
+            const jobs = []
+            for (const doc_id of Array.from(doc_ids)) {
+              ;(doc_id =>
+                jobs.push(cb =>
+                  UpdatesManager._processUncompressedUpdatesForDocWithLock(
+                    project_id,
+                    doc_id,
+                    temporary,
+                    cb
+                  )
+                ))(doc_id)
+            }
+            return async.parallelLimit(jobs, 5, callback)
+          }
+        )
+      }
+    )
   },
 
   // flush all outstanding changes
@@ -417,7 +418,7 @@ module.exports = UpdatesManager = {
       logger.log(
         {
           count: project_ids != null ? project_ids.length : undefined,
-          project_ids
+          project_ids,
         },
         'found projects'
       )
@@ -426,11 +427,11 @@ module.exports = UpdatesManager = {
       const selectedProjects =
         limit < 0 ? project_ids : project_ids.slice(0, limit)
       for (project_id of Array.from(selectedProjects)) {
-        ;((project_id) =>
-          jobs.push((cb) =>
+        ;(project_id =>
+          jobs.push(cb =>
             UpdatesManager.processUncompressedUpdatesForProject(
               project_id,
-              (err) => cb(null, { failed: err != null, project_id })
+              err => cb(null, { failed: err != null, project_id })
             )
           ))(project_id)
       }
@@ -460,7 +461,7 @@ module.exports = UpdatesManager = {
         return callback(null, {
           failed: failedProjects,
           succeeded: succeededProjects,
-          all: project_ids
+          all: project_ids,
         })
       })
     })
@@ -485,7 +486,7 @@ module.exports = UpdatesManager = {
           return callback(error)
         }
         // function to get doc_ids for each project
-        const task = (cb) =>
+        const task = cb =>
           async.concatSeries(
             all_project_ids,
             RedisManager.getDocIdsWithHistoryOps,
@@ -542,20 +543,22 @@ module.exports = UpdatesManager = {
     if (callback == null) {
       callback = function (error, updates) {}
     }
-    return UpdatesManager.getDocUpdates(project_id, doc_id, options, function (
-      error,
-      updates
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      return UpdatesManager.fillUserInfo(updates, function (error, updates) {
+    return UpdatesManager.getDocUpdates(
+      project_id,
+      doc_id,
+      options,
+      function (error, updates) {
         if (error != null) {
           return callback(error)
         }
-        return callback(null, updates)
-      })
-    })
+        return UpdatesManager.fillUserInfo(updates, function (error, updates) {
+          if (error != null) {
+            return callback(error)
+          }
+          return callback(null, updates)
+        })
+      }
+    )
   },
 
   getSummarizedProjectUpdates(project_id, options, callback) {
@@ -577,63 +580,65 @@ module.exports = UpdatesManager = {
         if (error != null) {
           return callback(error)
         }
-        return PackManager.makeProjectIterator(project_id, before, function (
-          err,
-          iterator
-        ) {
-          if (err != null) {
-            return callback(err)
-          }
-          // repeatedly get updates and pass them through the summariser to get an final output with user info
-          return async.whilst(
-            () =>
-              // console.log "checking iterator.done", iterator.done()
-              summarizedUpdates.length < options.min_count && !iterator.done(),
+        return PackManager.makeProjectIterator(
+          project_id,
+          before,
+          function (err, iterator) {
+            if (err != null) {
+              return callback(err)
+            }
+            // repeatedly get updates and pass them through the summariser to get an final output with user info
+            return async.whilst(
+              () =>
+                // console.log "checking iterator.done", iterator.done()
+                summarizedUpdates.length < options.min_count &&
+                !iterator.done(),
 
-            (cb) =>
-              iterator.next(function (err, partialUpdates) {
-                if (err != null) {
-                  return callback(err)
-                }
-                // logger.log {partialUpdates}, 'got partialUpdates'
-                if (partialUpdates.length === 0) {
-                  return cb()
-                } // # FIXME should try to avoid this happening
-                nextBeforeTimestamp =
-                  partialUpdates[partialUpdates.length - 1].meta.end_ts
-                // add the updates to the summary list
-                summarizedUpdates = UpdatesManager._summarizeUpdates(
-                  partialUpdates,
-                  summarizedUpdates
-                )
-                return cb()
-              }),
-
-            () =>
-              // finally done all updates
-              // console.log 'summarized Updates', summarizedUpdates
-              UpdatesManager.fillSummarizedUserInfo(
-                summarizedUpdates,
-                function (err, results) {
+              cb =>
+                iterator.next(function (err, partialUpdates) {
                   if (err != null) {
                     return callback(err)
                   }
-                  return callback(
-                    null,
-                    results,
-                    !iterator.done() ? nextBeforeTimestamp : undefined
+                  // logger.log {partialUpdates}, 'got partialUpdates'
+                  if (partialUpdates.length === 0) {
+                    return cb()
+                  } // # FIXME should try to avoid this happening
+                  nextBeforeTimestamp =
+                    partialUpdates[partialUpdates.length - 1].meta.end_ts
+                  // add the updates to the summary list
+                  summarizedUpdates = UpdatesManager._summarizeUpdates(
+                    partialUpdates,
+                    summarizedUpdates
                   )
-                }
-              )
-          )
-        })
+                  return cb()
+                }),
+
+              () =>
+                // finally done all updates
+                // console.log 'summarized Updates', summarizedUpdates
+                UpdatesManager.fillSummarizedUserInfo(
+                  summarizedUpdates,
+                  function (err, results) {
+                    if (err != null) {
+                      return callback(err)
+                    }
+                    return callback(
+                      null,
+                      results,
+                      !iterator.done() ? nextBeforeTimestamp : undefined
+                    )
+                  }
+                )
+            )
+          }
+        )
       }
     )
   },
 
   exportProject(projectId, consumer) {
     // Flush anything before collecting updates.
-    UpdatesManager.processUncompressedUpdatesForProject(projectId, (err) => {
+    UpdatesManager.processUncompressedUpdatesForProject(projectId, err => {
       if (err) return consumer(err)
 
       // Fetch all the packs.
@@ -646,7 +651,7 @@ module.exports = UpdatesManager = {
         async.whilst(
           () => !iterator.done(),
 
-          (cb) =>
+          cb =>
             iterator.next((err, updatesFromASinglePack) => {
               if (err) return cb(err)
 
@@ -656,7 +661,7 @@ module.exports = UpdatesManager = {
                 //  call.
                 return cb()
               }
-              updatesFromASinglePack.forEach((update) => {
+              updatesFromASinglePack.forEach(update => {
                 accumulatedUserIds.add(
                   // Super defensive access on update details.
                   String(update && update.meta && update.meta.user_id)
@@ -666,7 +671,7 @@ module.exports = UpdatesManager = {
               consumer(null, { updates: updatesFromASinglePack }, cb)
             }),
 
-          (err) => {
+          err => {
             if (err) return consumer(err)
 
             // Adding undefined can happen for broken updates.
@@ -674,7 +679,7 @@ module.exports = UpdatesManager = {
 
             consumer(null, {
               updates: [],
-              userIds: Array.from(accumulatedUserIds).sort()
+              userIds: Array.from(accumulatedUserIds).sort(),
             })
           }
         )
@@ -689,8 +694,8 @@ module.exports = UpdatesManager = {
     const jobs = []
     const fetchedUserInfo = {}
     for (const user_id in users) {
-      ;((user_id) =>
-        jobs.push((callback) =>
+      ;(user_id =>
+        jobs.push(callback =>
           WebApiManager.getUserInfo(user_id, function (error, userInfo) {
             if (error != null) {
               return callback(error)
@@ -722,22 +727,22 @@ module.exports = UpdatesManager = {
       }
     }
 
-    return UpdatesManager.fetchUserInfo(users, function (
-      error,
-      fetchedUserInfo
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      for (update of Array.from(updates)) {
-        ;({ user_id } = update.meta)
-        delete update.meta.user_id
-        if (UpdatesManager._validUserId(user_id)) {
-          update.meta.user = fetchedUserInfo[user_id]
+    return UpdatesManager.fetchUserInfo(
+      users,
+      function (error, fetchedUserInfo) {
+        if (error != null) {
+          return callback(error)
         }
+        for (update of Array.from(updates)) {
+          ;({ user_id } = update.meta)
+          delete update.meta.user_id
+          if (UpdatesManager._validUserId(user_id)) {
+            update.meta.user = fetchedUserInfo[user_id]
+          }
+        }
+        return callback(null, updates)
       }
-      return callback(null, updates)
-    })
+    )
   },
 
   fillSummarizedUserInfo(updates, callback) {
@@ -755,27 +760,27 @@ module.exports = UpdatesManager = {
       }
     }
 
-    return UpdatesManager.fetchUserInfo(users, function (
-      error,
-      fetchedUserInfo
-    ) {
-      if (error != null) {
-        return callback(error)
-      }
-      for (update of Array.from(updates)) {
-        user_ids = update.meta.user_ids || []
-        update.meta.users = []
-        delete update.meta.user_ids
-        for (user_id of Array.from(user_ids)) {
-          if (UpdatesManager._validUserId(user_id)) {
-            update.meta.users.push(fetchedUserInfo[user_id])
-          } else {
-            update.meta.users.push(null)
+    return UpdatesManager.fetchUserInfo(
+      users,
+      function (error, fetchedUserInfo) {
+        if (error != null) {
+          return callback(error)
+        }
+        for (update of Array.from(updates)) {
+          user_ids = update.meta.user_ids || []
+          update.meta.users = []
+          delete update.meta.user_ids
+          for (user_id of Array.from(user_ids)) {
+            if (UpdatesManager._validUserId(user_id)) {
+              update.meta.users.push(fetchedUserInfo[user_id])
+            } else {
+              update.meta.users.push(null)
+            }
           }
         }
+        return callback(null, updates)
       }
-      return callback(null, updates)
-    })
+    )
   },
 
   _validUserId(user_id) {
@@ -830,7 +835,7 @@ module.exports = UpdatesManager = {
         // check if the user in this update is already present in the earliest update,
         // if not, add them to the users list of the earliest update
         earliestUpdate.meta.user_ids = _.union(earliestUpdate.meta.user_ids, [
-          update.meta.user_id
+          update.meta.user_id,
         ])
 
         doc_id = update.doc_id.toString()
@@ -841,7 +846,7 @@ module.exports = UpdatesManager = {
         } else {
           earliestUpdate.docs[doc_id] = {
             fromV: update.v,
-            toV: update.v
+            toV: update.v,
           }
         }
 
@@ -858,14 +863,14 @@ module.exports = UpdatesManager = {
           meta: {
             user_ids: [],
             start_ts: update.meta.start_ts,
-            end_ts: update.meta.end_ts
+            end_ts: update.meta.end_ts,
           },
-          docs: {}
+          docs: {},
         }
 
         newUpdate.docs[update.doc_id.toString()] = {
           fromV: update.v,
-          toV: update.v
+          toV: update.v,
         }
         newUpdate.meta.user_ids.push(update.meta.user_id)
         summarizedUpdates.push(newUpdate)
@@ -873,7 +878,7 @@ module.exports = UpdatesManager = {
     }
 
     return summarizedUpdates
-  }
+  },
 }
 
 function __guard__(value, transform) {
diff --git a/services/track-changes/app/js/WebApiManager.js b/services/track-changes/app/js/WebApiManager.js
index b1bd6de063..b0706d8e71 100644
--- a/services/track-changes/app/js/WebApiManager.js
+++ b/services/track-changes/app/js/WebApiManager.js
@@ -36,8 +36,8 @@ module.exports = WebApiManager = {
         auth: {
           user: Settings.apis.web.user,
           pass: Settings.apis.web.pass,
-          sendImmediately: true
-        }
+          sendImmediately: true,
+        },
       },
       function (error, res, body) {
         if (error != null) {
@@ -86,7 +86,7 @@ module.exports = WebApiManager = {
         id: user.id,
         email: user.email,
         first_name: user.first_name,
-        last_name: user.last_name
+        last_name: user.last_name,
       })
     })
   },
@@ -112,5 +112,5 @@ module.exports = WebApiManager = {
       }
       return callback(null, project)
     })
-  }
+  },
 }
diff --git a/services/track-changes/app/js/mongodb.js b/services/track-changes/app/js/mongodb.js
index 5b4f56dce8..a345d5ce70 100644
--- a/services/track-changes/app/js/mongodb.js
+++ b/services/track-changes/app/js/mongodb.js
@@ -38,5 +38,5 @@ module.exports = {
   db,
   ObjectId,
   closeDb,
-  waitForDb
+  waitForDb,
 }
diff --git a/services/track-changes/app/lib/diff_match_patch.js b/services/track-changes/app/lib/diff_match_patch.js
index c4864d7bde..aeb2b1c570 100644
--- a/services/track-changes/app/lib/diff_match_patch.js
+++ b/services/track-changes/app/lib/diff_match_patch.js
@@ -178,7 +178,7 @@ diff_match_patch.prototype.diff_compute_ = function (
     diffs = [
       [DIFF_INSERT, longtext.substring(0, i)],
       [DIFF_EQUAL, shorttext],
-      [DIFF_INSERT, longtext.substring(i + shorttext.length)]
+      [DIFF_INSERT, longtext.substring(i + shorttext.length)],
     ]
     // Swap insertions for deletions if diff is reversed.
     if (text1.length > text2.length) {
@@ -192,7 +192,7 @@ diff_match_patch.prototype.diff_compute_ = function (
     // After the previous speedup, the character can't be an equality.
     return [
       [DIFF_DELETE, text1],
-      [DIFF_INSERT, text2]
+      [DIFF_INSERT, text2],
     ]
   }
 
@@ -415,7 +415,7 @@ diff_match_patch.prototype.diff_bisect_ = function (text1, text2, deadline) {
   // number of diffs equals number of characters, no commonality at all.
   return [
     [DIFF_DELETE, text1],
-    [DIFF_INSERT, text2]
+    [DIFF_INSERT, text2],
   ]
 }
 
@@ -716,7 +716,7 @@ diff_match_patch.prototype.diff_halfMatch_ = function (text1, text2) {
         best_longtext_b,
         best_shorttext_a,
         best_shorttext_b,
-        best_common
+        best_common,
       ]
     } else {
       return null
@@ -809,7 +809,7 @@ diff_match_patch.prototype.diff_cleanupSemantic = function (diffs) {
         // Duplicate record.
         diffs.splice(equalities[equalitiesLength - 1], 0, [
           DIFF_DELETE,
-          lastequality
+          lastequality,
         ])
         // Change second copy to insert.
         diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT
@@ -859,7 +859,7 @@ diff_match_patch.prototype.diff_cleanupSemantic = function (diffs) {
           // Overlap found.  Insert an equality and trim the surrounding edits.
           diffs.splice(pointer, 0, [
             DIFF_EQUAL,
-            insertion.substring(0, overlap_length1)
+            insertion.substring(0, overlap_length1),
           ])
           diffs[pointer - 1][1] = deletion.substring(
             0,
@@ -877,7 +877,7 @@ diff_match_patch.prototype.diff_cleanupSemantic = function (diffs) {
           // Insert an equality and swap and trim the surrounding edits.
           diffs.splice(pointer, 0, [
             DIFF_EQUAL,
-            deletion.substring(0, overlap_length2)
+            deletion.substring(0, overlap_length2),
           ])
           diffs[pointer - 1][0] = DIFF_INSERT
           diffs[pointer - 1][1] = insertion.substring(
@@ -1093,7 +1093,7 @@ diff_match_patch.prototype.diff_cleanupEfficiency = function (diffs) {
         // Duplicate record.
         diffs.splice(equalities[equalitiesLength - 1], 0, [
           DIFF_DELETE,
-          lastequality
+          lastequality,
         ])
         // Change second copy to insert.
         diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT
@@ -1156,13 +1156,12 @@ diff_match_patch.prototype.diff_cleanupMerge = function (diffs) {
                 diffs[pointer - count_delete - count_insert - 1][0] ==
                   DIFF_EQUAL
               ) {
-                diffs[
-                  pointer - count_delete - count_insert - 1
-                ][1] += text_insert.substring(0, commonlength)
+                diffs[pointer - count_delete - count_insert - 1][1] +=
+                  text_insert.substring(0, commonlength)
               } else {
                 diffs.splice(0, 0, [
                   DIFF_EQUAL,
-                  text_insert.substring(0, commonlength)
+                  text_insert.substring(0, commonlength),
                 ])
                 pointer++
               }
@@ -1189,12 +1188,12 @@ diff_match_patch.prototype.diff_cleanupMerge = function (diffs) {
           if (count_delete === 0) {
             diffs.splice(pointer - count_insert, count_delete + count_insert, [
               DIFF_INSERT,
-              text_insert
+              text_insert,
             ])
           } else if (count_insert === 0) {
             diffs.splice(pointer - count_delete, count_delete + count_insert, [
               DIFF_DELETE,
-              text_delete
+              text_delete,
             ])
           } else {
             diffs.splice(
diff --git a/services/track-changes/config/settings.defaults.js b/services/track-changes/config/settings.defaults.js
index 38ecce723a..faa8660b70 100755
--- a/services/track-changes/config/settings.defaults.js
+++ b/services/track-changes/config/settings.defaults.js
@@ -6,18 +6,18 @@ module.exports = {
   mongo: {
     options: {
       useUnifiedTopology:
-        (process.env.MONGO_USE_UNIFIED_TOPOLOGY || 'true') === 'true'
+        (process.env.MONGO_USE_UNIFIED_TOPOLOGY || 'true') === 'true',
     },
     url:
       process.env.MONGO_CONNECTION_STRING ||
-      `mongodb://${process.env.MONGO_HOST || 'localhost'}/sharelatex`
+      `mongodb://${process.env.MONGO_HOST || 'localhost'}/sharelatex`,
   },
 
   internal: {
     trackchanges: {
       port: 3015,
-      host: process.env.LISTEN_ADDRESS || 'localhost'
-    }
+      host: process.env.LISTEN_ADDRESS || 'localhost',
+    },
   },
   apis: {
     documentupdater: {
@@ -25,18 +25,18 @@ module.exports = {
         process.env.DOCUMENT_UPDATER_HOST ||
         process.env.DOCUPDATER_HOST ||
         'localhost'
-      }:3003`
+      }:3003`,
     },
     docstore: {
-      url: `http://${process.env.DOCSTORE_HOST || 'localhost'}:3016`
+      url: `http://${process.env.DOCSTORE_HOST || 'localhost'}:3016`,
     },
     web: {
       url: `http://${
         process.env.WEB_API_HOST || process.env.WEB_HOST || 'localhost'
       }:${process.env.WEB_API_PORT || process.env.WEB_PORT || 3000}`,
       user: process.env.WEB_API_USER || 'sharelatex',
-      pass: process.env.WEB_API_PASSWORD || 'password'
-    }
+      pass: process.env.WEB_API_PASSWORD || 'password',
+    },
   },
   redis: {
     lock: {
@@ -49,8 +49,8 @@ module.exports = {
         },
         historyIndexLock({ project_id: projectId }) {
           return `HistoryIndexLock:{${projectId}}`
-        }
-      }
+        },
+      },
     },
     history: {
       host: process.env.REDIS_HOST || 'localhost',
@@ -62,9 +62,9 @@ module.exports = {
         },
         docsWithHistoryOps({ project_id: projectId }) {
           return `DocsWithHistoryOps:{${projectId}}`
-        }
-      }
-    }
+        },
+      },
+    },
   },
 
   trackchanges: {
@@ -72,19 +72,19 @@ module.exports = {
       key: process.env.AWS_ACCESS_KEY_ID,
       secret: process.env.AWS_SECRET_ACCESS_KEY,
       endpoint: process.env.AWS_S3_ENDPOINT,
-      pathStyle: process.env.AWS_S3_PATH_STYLE === 'true'
+      pathStyle: process.env.AWS_S3_PATH_STYLE === 'true',
     },
     stores: {
-      doc_history: process.env.AWS_BUCKET
+      doc_history: process.env.AWS_BUCKET,
     },
-    continueOnError: process.env.TRACK_CHANGES_CONTINUE_ON_ERROR || false
+    continueOnError: process.env.TRACK_CHANGES_CONTINUE_ON_ERROR || false,
   },
 
   path: {
-    dumpFolder: Path.join(TMP_DIR, 'dumpFolder')
+    dumpFolder: Path.join(TMP_DIR, 'dumpFolder'),
   },
 
   sentry: {
-    dsn: process.env.SENTRY_DSN
-  }
+    dsn: process.env.SENTRY_DSN,
+  },
 }
diff --git a/services/track-changes/test/acceptance/js/AppendingUpdatesTests.js b/services/track-changes/test/acceptance/js/AppendingUpdatesTests.js
index c0bb0b07ae..9292005ba7 100644
--- a/services/track-changes/test/acceptance/js/AppendingUpdatesTests.js
+++ b/services/track-changes/test/acceptance/js/AppendingUpdatesTests.js
@@ -39,20 +39,20 @@ describe('Appending doc ops to the history', function () {
           {
             op: [{ i: 'f', p: 3 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
+            v: 3,
           },
           {
             op: [{ i: 'o', p: 4 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 4
+            v: 4,
           },
           {
             op: [{ i: 'o', p: 5 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 5
-          }
+            v: 5,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -76,8 +76,8 @@ describe('Appending doc ops to the history', function () {
       return expect(this.updates[0].pack[0].op).to.deep.equal([
         {
           p: 3,
-          i: 'foo'
-        }
+          i: 'foo',
+        },
       ])
     })
 
@@ -121,20 +121,20 @@ describe('Appending doc ops to the history', function () {
           {
             op: [{ i: 'f', p: 3 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
+            v: 3,
           },
           {
             op: [{ i: 'o', p: 4 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 4
+            v: 4,
           },
           {
             op: [{ i: 'o', p: 5 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 5
-          }
+            v: 5,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -162,20 +162,20 @@ describe('Appending doc ops to the history', function () {
             {
               op: [{ i: 'b', p: 6 }],
               meta: { ts: Date.now(), user_id: this.user_id },
-              v: 6
+              v: 6,
             },
             {
               op: [{ i: 'a', p: 7 }],
               meta: { ts: Date.now(), user_id: this.user_id },
-              v: 7
+              v: 7,
             },
             {
               op: [{ i: 'r', p: 8 }],
               meta: { ts: Date.now(), user_id: this.user_id },
-              v: 8
-            }
+              v: 8,
+            },
           ],
-          (error) => {
+          error => {
             if (error != null) {
               throw error
             }
@@ -199,8 +199,8 @@ describe('Appending doc ops to the history', function () {
         return expect(this.updates[0].pack[1].op).to.deep.equal([
           {
             p: 6,
-            i: 'bar'
-          }
+            i: 'bar',
+          },
         ])
       })
 
@@ -219,20 +219,20 @@ describe('Appending doc ops to the history', function () {
             {
               op: [{ i: 'b', p: 6 }],
               meta: { ts: Date.now() + oneDay, user_id: this.user_id },
-              v: 6
+              v: 6,
             },
             {
               op: [{ i: 'a', p: 7 }],
               meta: { ts: Date.now() + oneDay, user_id: this.user_id },
-              v: 7
+              v: 7,
             },
             {
               op: [{ i: 'r', p: 8 }],
               meta: { ts: Date.now() + oneDay, user_id: this.user_id },
-              v: 8
-            }
+              v: 8,
+            },
           ],
-          (error) => {
+          error => {
             if (error != null) {
               throw error
             }
@@ -256,14 +256,14 @@ describe('Appending doc ops to the history', function () {
         expect(this.updates[0].pack[0].op).to.deep.equal([
           {
             p: 3,
-            i: 'foo'
-          }
+            i: 'foo',
+          },
         ])
         return expect(this.updates[0].pack[1].op).to.deep.equal([
           {
             p: 6,
-            i: 'bar'
-          }
+            i: 'bar',
+          },
         ])
       })
     })
@@ -281,7 +281,7 @@ describe('Appending doc ops to the history', function () {
         updates.push({
           op: [{ i: 'a', p: 0 }],
           meta: { ts: Date.now(), user_id: this.user_id },
-          v: i
+          v: i,
         })
         this.expectedOp[0].i = `a${this.expectedOp[0].i}`
       }
@@ -290,7 +290,7 @@ describe('Appending doc ops to the history', function () {
         this.project_id,
         this.doc_id,
         updates,
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -334,22 +334,22 @@ describe('Appending doc ops to the history', function () {
             op: [
               { i: 'f', p: 3 },
               { i: 'o', p: 4 },
-              { i: 'o', p: 5 }
+              { i: 'o', p: 5 },
             ],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
+            v: 3,
           },
           {
             op: [
               { i: 'b', p: 6 },
               { i: 'a', p: 7 },
-              { i: 'r', p: 8 }
+              { i: 'r', p: 8 },
             ],
             meta: { ts: Date.now() + oneDay, user_id: this.user_id },
-            v: 4
-          }
+            v: 4,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -373,14 +373,14 @@ describe('Appending doc ops to the history', function () {
       expect(this.updates[0].pack[0].op).to.deep.equal([
         {
           p: 3,
-          i: 'foo'
-        }
+          i: 'foo',
+        },
       ])
       return expect(this.updates[0].pack[1].op).to.deep.equal([
         {
           p: 6,
-          i: 'bar'
-        }
+          i: 'bar',
+        },
       ])
     })
 
@@ -404,15 +404,15 @@ describe('Appending doc ops to the history', function () {
           {
             op: [],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
+            v: 3,
           },
           {
             op: [{ i: 'foo', p: 3 }],
             meta: { ts: Date.now() + oneDay, user_id: this.user_id },
-            v: 4
-          }
+            v: 4,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -440,8 +440,8 @@ describe('Appending doc ops to the history', function () {
       return expect(this.updates[0].pack[1].op).to.deep.equal([
         {
           p: 3,
-          i: 'foo'
-        }
+          i: 'foo',
+        },
       ])
     })
 
@@ -464,13 +464,13 @@ describe('Appending doc ops to the history', function () {
           {
             op: [
               { c: 'foo', p: 3 },
-              { d: 'bar', p: 6 }
+              { d: 'bar', p: 6 },
             ],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
-          }
+            v: 3,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -492,7 +492,7 @@ describe('Appending doc ops to the history', function () {
 
     it('should ignore the comment op', function () {
       return expect(this.updates[0].pack[0].op).to.deep.equal([
-        { d: 'bar', p: 6 }
+        { d: 'bar', p: 6 },
       ])
     })
 
@@ -515,10 +515,10 @@ describe('Appending doc ops to the history', function () {
           {
             op: [{ i: 'f', p: 3 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
-          }
+            v: 3,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -557,10 +557,10 @@ describe('Appending doc ops to the history', function () {
           {
             op: [{ i: 'f', p: 3 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
-          }
+            v: 3,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
diff --git a/services/track-changes/test/acceptance/js/ArchivingUpdatesTests.js b/services/track-changes/test/acceptance/js/ArchivingUpdatesTests.js
index 4f693e70a1..09435bc80c 100644
--- a/services/track-changes/test/acceptance/js/ArchivingUpdatesTests.js
+++ b/services/track-changes/test/acceptance/js/ArchivingUpdatesTests.js
@@ -32,9 +32,9 @@ describe('Archiving updates', function () {
       __guard__(
         __guard__(
           Settings != null ? Settings.trackchanges : undefined,
-          (x1) => x1.s3
+          x1 => x1.s3
         ),
-        (x) => x.key.length
+        x => x.key.length
       ) < 1
     ) {
       const message = new Error('s3 keys not setup, this test setup will fail')
@@ -57,8 +57,8 @@ describe('Archiving updates', function () {
 
     MockWebApi.projects[this.project_id] = {
       features: {
-        versioning: true
-      }
+        versioning: true,
+      },
     }
     sinon.spy(MockWebApi, 'getProjectDetails')
 
@@ -66,13 +66,13 @@ describe('Archiving updates', function () {
       email: 'user@sharelatex.com',
       first_name: 'Leo',
       last_name: 'Lion',
-      id: this.user_id
+      id: this.user_id,
     }
     sinon.spy(MockWebApi, 'getUserInfo')
 
     MockDocStoreApi.docs[this.doc_id] = this.doc = {
       _id: this.doc_id,
-      project_id: this.project_id
+      project_id: this.project_id,
     }
     sinon.spy(MockDocStoreApi, 'getAllDoc')
 
@@ -85,15 +85,15 @@ describe('Archiving updates', function () {
       this.updates.push({
         op: [{ i: 'a', p: 0 }],
         meta: { ts: this.now + (i - 2048) * this.hours, user_id: this.user_id },
-        v: 2 * i + 1
+        v: 2 * i + 1,
       })
       this.updates.push({
         op: [{ i: 'b', p: 0 }],
         meta: {
           ts: this.now + (i - 2048) * this.hours + 10 * this.minutes,
-          user_id: this.user_id_2
+          user_id: this.user_id_2,
         },
-        v: 2 * i + 2
+        v: 2 * i + 2,
       })
     }
     TrackChangesApp.ensureRunning(() => {
@@ -101,14 +101,14 @@ describe('Archiving updates', function () {
         this.project_id,
         this.doc_id,
         this.updates,
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
           return TrackChangesClient.flushDoc(
             this.project_id,
             this.doc_id,
-            (error) => {
+            error => {
               if (error != null) {
                 throw error
               }
@@ -163,7 +163,7 @@ describe('Archiving updates', function () {
         const expectedExportedUpdates = this.updates
           .slice()
           .reverse()
-          .map((update) => {
+          .map(update => {
             // clone object, updates are created once in before handler
             const exportedUpdate = Object.assign({}, update)
             exportedUpdate.meta = Object.assign({}, update.meta)
@@ -180,7 +180,7 @@ describe('Archiving updates', function () {
         expect(this.exportedUpdates).to.deep.equal(expectedExportedUpdates)
         expect(this.exportedUserIds).to.deep.equal([
           this.user_id,
-          this.user_id_2
+          this.user_id_2,
         ])
       })
     })
@@ -192,16 +192,12 @@ describe('Archiving updates', function () {
 
   describe("archiving a doc's updates", function () {
     before(function (done) {
-      TrackChangesClient.pushDocHistory(
-        this.project_id,
-        this.doc_id,
-        (error) => {
-          if (error != null) {
-            throw error
-          }
-          return done()
+      TrackChangesClient.pushDocHistory(this.project_id, this.doc_id, error => {
+        if (error != null) {
+          throw error
         }
-      )
+        return done()
+      })
       return null
     })
 
@@ -222,7 +218,7 @@ describe('Archiving updates', function () {
       return db.docHistory.deleteMany(
         {
           doc_id: ObjectId(this.doc_id),
-          expiresAt: { $exists: true }
+          expiresAt: { $exists: true },
         },
         (err, result) => {
           if (typeof error !== 'undefined' && error !== null) {
@@ -295,16 +291,12 @@ describe('Archiving updates', function () {
 
   return describe("unarchiving a doc's updates", function () {
     before(function (done) {
-      TrackChangesClient.pullDocHistory(
-        this.project_id,
-        this.doc_id,
-        (error) => {
-          if (error != null) {
-            throw error
-          }
-          return done()
+      TrackChangesClient.pullDocHistory(this.project_id, this.doc_id, error => {
+        if (error != null) {
+          throw error
         }
-      )
+        return done()
+      })
       return null
     })
 
diff --git a/services/track-changes/test/acceptance/js/FlushingUpdatesTests.js b/services/track-changes/test/acceptance/js/FlushingUpdatesTests.js
index 99851d9515..65e5ecc468 100644
--- a/services/track-changes/test/acceptance/js/FlushingUpdatesTests.js
+++ b/services/track-changes/test/acceptance/js/FlushingUpdatesTests.js
@@ -40,17 +40,17 @@ describe('Flushing updates', function () {
           {
             op: [{ i: 'f', p: 3 }],
             meta: { ts: Date.now(), user_id: this.user_id },
-            v: 3
-          }
+            v: 3,
+          },
         ],
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
           return TrackChangesClient.flushDoc(
             this.project_id,
             this.doc_id,
-            (error) => {
+            error => {
               if (error != null) {
                 throw error
               }
@@ -67,8 +67,8 @@ describe('Flushing updates', function () {
         expect(updates[0].pack[0].op).to.deep.equal([
           {
             p: 3,
-            i: 'f'
-          }
+            i: 'f',
+          },
         ])
         return done()
       })
@@ -87,8 +87,8 @@ describe('Flushing updates', function () {
 
         MockWebApi.projects[this.project_id] = {
           features: {
-            versioning: true
-          }
+            versioning: true,
+          },
         }
 
         TrackChangesClient.pushRawUpdates(
@@ -98,19 +98,19 @@ describe('Flushing updates', function () {
             {
               op: [{ i: 'g', p: 2 }],
               meta: { ts: Date.now() - 2 * this.weeks, user_id: this.user_id },
-              v: 2
+              v: 2,
             },
             {
               op: [{ i: 'f', p: 3 }],
               meta: { ts: Date.now(), user_id: this.user_id },
-              v: 3
-            }
+              v: 3,
+            },
           ],
-          (error) => {
+          error => {
             if (error != null) {
               throw error
             }
-            return TrackChangesClient.flushProject(this.project_id, (error) => {
+            return TrackChangesClient.flushProject(this.project_id, error => {
               if (error != null) {
                 throw error
               }
@@ -154,8 +154,8 @@ describe('Flushing updates', function () {
 
         MockWebApi.projects[this.project_id] = {
           features: {
-            versioning: false
-          }
+            versioning: false,
+          },
         }
 
         TrackChangesClient.pushRawUpdates(
@@ -165,19 +165,19 @@ describe('Flushing updates', function () {
             {
               op: [{ i: 'g', p: 2 }],
               meta: { ts: Date.now() - 2 * this.weeks, user_id: this.user_id },
-              v: 2
+              v: 2,
             },
             {
               op: [{ i: 'f', p: 3 }],
               meta: { ts: Date.now(), user_id: this.user_id },
-              v: 3
-            }
+              v: 3,
+            },
           ],
-          (error) => {
+          error => {
             if (error != null) {
               throw error
             }
-            return TrackChangesClient.flushProject(this.project_id, (error) => {
+            return TrackChangesClient.flushProject(this.project_id, error => {
               if (error != null) {
                 throw error
               }
@@ -210,13 +210,13 @@ describe('Flushing updates', function () {
 
         MockWebApi.projects[this.project_id] = {
           features: {
-            versioning: false
-          }
+            versioning: false,
+          },
         }
 
         TrackChangesClient.setPreserveHistoryForProject(
           this.project_id,
-          (error) => {
+          error => {
             if (error != null) {
               throw error
             }
@@ -228,23 +228,23 @@ describe('Flushing updates', function () {
                   op: [{ i: 'g', p: 2 }],
                   meta: {
                     ts: Date.now() - 2 * this.weeks,
-                    user_id: this.user_id
+                    user_id: this.user_id,
                   },
-                  v: 2
+                  v: 2,
                 },
                 {
                   op: [{ i: 'f', p: 3 }],
                   meta: { ts: Date.now(), user_id: this.user_id },
-                  v: 3
-                }
+                  v: 3,
+                },
               ],
-              (error) => {
+              error => {
                 if (error != null) {
                   throw error
                 }
                 return TrackChangesClient.flushProject(
                   this.project_id,
-                  (error) => {
+                  error => {
                     if (error != null) {
                       throw error
                     }
diff --git a/services/track-changes/test/acceptance/js/GettingADiffTests.js b/services/track-changes/test/acceptance/js/GettingADiffTests.js
index b0390db9e4..f2de3d7d7f 100644
--- a/services/track-changes/test/acceptance/js/GettingADiffTests.js
+++ b/services/track-changes/test/acceptance/js/GettingADiffTests.js
@@ -35,7 +35,7 @@ describe('Getting a diff', function () {
       email: 'user@sharelatex.com',
       first_name: 'Leo',
       last_name: 'Lion',
-      id: this.user_id
+      id: this.user_id,
     }
     sinon.spy(MockWebApi, 'getUserInfo')
 
@@ -45,23 +45,23 @@ describe('Getting a diff', function () {
       {
         op: [{ i: 'one ', p: 0 }],
         meta: { ts: this.from - twoMinutes, user_id: this.user_id },
-        v: 3
+        v: 3,
       },
       {
         op: [{ i: 'two ', p: 4 }],
         meta: { ts: this.from + twoMinutes, user_id: this.user_id },
-        v: (this.fromVersion = 4)
+        v: (this.fromVersion = 4),
       },
       {
         op: [{ i: 'three ', p: 8 }],
         meta: { ts: this.to - twoMinutes, user_id: this.user_id },
-        v: (this.toVersion = 5)
+        v: (this.toVersion = 5),
       },
       {
         op: [{ i: 'four', p: 14 }],
         meta: { ts: this.to + twoMinutes, user_id: this.user_id },
-        v: 6
-      }
+        v: 6,
+      },
     ]
     this.lines = ['one two three four']
     this.expected_diff = [
@@ -71,21 +71,21 @@ describe('Getting a diff', function () {
         meta: {
           start_ts: this.from + twoMinutes,
           end_ts: this.to - twoMinutes,
-          user: this.user
-        }
-      }
+          user: this.user,
+        },
+      },
     ]
 
     MockDocUpdaterApi.docs[this.doc_id] = {
       lines: this.lines,
-      version: 7
+      version: 7,
     }
     TrackChangesApp.ensureRunning(() => {
       return TrackChangesClient.pushRawUpdates(
         this.project_id,
         this.doc_id,
         this.updates,
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
diff --git a/services/track-changes/test/acceptance/js/GettingUpdatesTests.js b/services/track-changes/test/acceptance/js/GettingUpdatesTests.js
index f58c9b729f..d3fce21171 100644
--- a/services/track-changes/test/acceptance/js/GettingUpdatesTests.js
+++ b/services/track-changes/test/acceptance/js/GettingUpdatesTests.js
@@ -33,15 +33,15 @@ describe('Getting updates', function () {
 
     MockWebApi.projects[this.project_id] = {
       features: {
-        versioning: true
-      }
+        versioning: true,
+      },
     }
 
     MockWebApi.users[this.user_id] = this.user = {
       email: 'user@sharelatex.com',
       first_name: 'Leo',
       last_name: 'Lion',
-      id: this.user_id
+      id: this.user_id,
     }
     sinon.spy(MockWebApi, 'getUserInfo')
 
@@ -51,14 +51,14 @@ describe('Getting updates', function () {
         op: [{ i: 'a', p: 0 }],
         meta: {
           ts: this.now - (9 - i) * this.hours - 2 * this.minutes,
-          user_id: this.user_id
+          user_id: this.user_id,
         },
-        v: 2 * i + 1
+        v: 2 * i + 1,
       })
       this.updates.push({
         op: [{ i: 'b', p: 0 }],
         meta: { ts: this.now - (9 - i) * this.hours, user_id: this.user_id },
-        v: 2 * i + 2
+        v: 2 * i + 2,
       })
     }
     this.updates[0].meta.user_id = this.deleted_user_id
@@ -68,7 +68,7 @@ describe('Getting updates', function () {
         this.project_id,
         this.doc_id,
         this.updates,
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -82,7 +82,7 @@ describe('Getting updates', function () {
     after() {
       MockWebApi.getUserInfo.restore()
       return null
-    }
+    },
   })
 
   describe('getting updates up to the limit', function () {
@@ -118,25 +118,25 @@ describe('Getting updates', function () {
           meta: {
             start_ts: this.to - 2 * this.minutes,
             end_ts: this.to,
-            users: [this.user]
-          }
+            users: [this.user],
+          },
         },
         {
           docs: docs2,
           meta: {
             start_ts: this.to - 1 * this.hours - 2 * this.minutes,
             end_ts: this.to - 1 * this.hours,
-            users: [this.user]
-          }
+            users: [this.user],
+          },
         },
         {
           docs: docs3,
           meta: {
             start_ts: this.to - 2 * this.hours - 2 * this.minutes,
             end_ts: this.to - 2 * this.hours,
-            users: [this.user]
-          }
-        }
+            users: [this.user],
+          },
+        },
       ])
     })
   })
@@ -168,17 +168,17 @@ describe('Getting updates', function () {
           meta: {
             start_ts: this.to - 8 * this.hours - 2 * this.minutes,
             end_ts: this.to - 8 * this.hours,
-            users: [this.user]
-          }
+            users: [this.user],
+          },
         },
         {
           docs: docs2,
           meta: {
             start_ts: this.to - 9 * this.hours - 2 * this.minutes,
             end_ts: this.to - 9 * this.hours,
-            users: [this.user, null]
-          }
-        }
+            users: [this.user, null],
+          },
+        },
       ])
     })
   })
diff --git a/services/track-changes/test/acceptance/js/LockManagerTests.js b/services/track-changes/test/acceptance/js/LockManagerTests.js
index 47341f7891..104e7c3220 100644
--- a/services/track-changes/test/acceptance/js/LockManagerTests.js
+++ b/services/track-changes/test/acceptance/js/LockManagerTests.js
@@ -27,24 +27,24 @@ describe('Locking document', function () {
       LockManager.LOCK_TTL = 1 // second
       LockManager.runWithLock(
         'doc123',
-        (releaseA) => {
+        releaseA => {
           // we create a lock A and allow it to expire in redis
           return setTimeout(
             () =>
               // now we create a new lock B and try to release A
               LockManager.runWithLock(
                 'doc123',
-                (releaseB) => {
+                releaseB => {
                   return releaseA()
                 }, // try to release lock A to see if it wipes out lock B
-                (error) => {}
+                error => {}
               ),
 
             // we never release lock B so nothing should happen here
             1500
           )
         }, // enough time to wait until the lock has expired
-        (error) =>
+        error =>
           // we get here after trying to release lock A
           done()
       )
diff --git a/services/track-changes/test/acceptance/js/RestoringVersions.js b/services/track-changes/test/acceptance/js/RestoringVersions.js
index 1e9f0d43a5..312d92bef9 100644
--- a/services/track-changes/test/acceptance/js/RestoringVersions.js
+++ b/services/track-changes/test/acceptance/js/RestoringVersions.js
@@ -35,23 +35,23 @@ describe('Restoring a version', function () {
       {
         op: [{ i: 'one ', p: 0 }],
         meta: { ts: this.now - 6 * minutes, user_id: this.user_id },
-        v: 3
+        v: 3,
       },
       {
         op: [{ i: 'two ', p: 4 }],
         meta: { ts: this.now - 4 * minutes, user_id: this.user_id },
-        v: 4
+        v: 4,
       },
       {
         op: [{ i: 'three ', p: 8 }],
         meta: { ts: this.now - 2 * minutes, user_id: this.user_id },
-        v: 5
+        v: 5,
       },
       {
         op: [{ i: 'four', p: 14 }],
         meta: { ts: this.now, user_id: this.user_id },
-        v: 6
-      }
+        v: 6,
+      },
     ]
     this.lines = ['one two three four']
     this.restored_lines = ['one two ']
@@ -61,12 +61,12 @@ describe('Restoring a version', function () {
       email: 'user@sharelatex.com',
       first_name: 'Leo',
       last_name: 'Lion',
-      id: this.user_id
+      id: this.user_id,
     }
 
     MockDocUpdaterApi.docs[this.doc_id] = {
       lines: this.lines,
-      version: 7
+      version: 7,
     }
 
     TrackChangesApp.ensureRunning(() => {
@@ -74,7 +74,7 @@ describe('Restoring a version', function () {
         this.project_id,
         this.doc_id,
         this.updates,
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -83,7 +83,7 @@ describe('Restoring a version', function () {
             this.doc_id,
             this.beforeVersion,
             this.user_id,
-            (error) => {
+            error => {
               if (error != null) {
                 throw error
               }
diff --git a/services/track-changes/test/acceptance/js/helpers/MockDocStoreApi.js b/services/track-changes/test/acceptance/js/helpers/MockDocStoreApi.js
index b1ebcf9cef..12787770a4 100644
--- a/services/track-changes/test/acceptance/js/helpers/MockDocStoreApi.js
+++ b/services/track-changes/test/acceptance/js/helpers/MockDocStoreApi.js
@@ -39,16 +39,16 @@ module.exports = MockDocUpdaterApi = {
     })
 
     return app
-      .listen(3016, (error) => {
+      .listen(3016, error => {
         if (error != null) {
           throw error
         }
       })
-      .on('error', (error) => {
+      .on('error', error => {
         console.error('error starting MockDocStoreApi:', error.message)
         return process.exit(1)
       })
-  }
+  },
 }
 
 MockDocUpdaterApi.run()
diff --git a/services/track-changes/test/acceptance/js/helpers/MockDocUpdaterApi.js b/services/track-changes/test/acceptance/js/helpers/MockDocUpdaterApi.js
index b3b5e23ba7..1c39ff5dbc 100644
--- a/services/track-changes/test/acceptance/js/helpers/MockDocUpdaterApi.js
+++ b/services/track-changes/test/acceptance/js/helpers/MockDocUpdaterApi.js
@@ -74,16 +74,16 @@ module.exports = MockDocUpdaterApi = {
     })
 
     return app
-      .listen(3003, (error) => {
+      .listen(3003, error => {
         if (error != null) {
           throw error
         }
       })
-      .on('error', (error) => {
+      .on('error', error => {
         console.error('error starting MockDocUpdaterApi:', error.message)
         return process.exit(1)
       })
-  }
+  },
 }
 
 MockDocUpdaterApi.run()
diff --git a/services/track-changes/test/acceptance/js/helpers/MockWebApi.js b/services/track-changes/test/acceptance/js/helpers/MockWebApi.js
index b7ebbc876f..db6968dc54 100644
--- a/services/track-changes/test/acceptance/js/helpers/MockWebApi.js
+++ b/services/track-changes/test/acceptance/js/helpers/MockWebApi.js
@@ -61,16 +61,16 @@ module.exports = MockWebApi = {
     })
 
     return app
-      .listen(3000, (error) => {
+      .listen(3000, error => {
         if (error != null) {
           throw error
         }
       })
-      .on('error', (error) => {
+      .on('error', error => {
         console.error('error starting MockWebApiServer:', error.message)
         return process.exit(1)
       })
-  }
+  },
 }
 
 MockWebApi.run()
diff --git a/services/track-changes/test/acceptance/js/helpers/TrackChangesApp.js b/services/track-changes/test/acceptance/js/helpers/TrackChangesApp.js
index 7840b1f569..f6ff0cc024 100644
--- a/services/track-changes/test/acceptance/js/helpers/TrackChangesApp.js
+++ b/services/track-changes/test/acceptance/js/helpers/TrackChangesApp.js
@@ -38,10 +38,10 @@ module.exports = {
           Settings.internal != null
             ? Settings.internal.trackchanges
             : undefined,
-          (x) => x.port
+          x => x.port
         ),
         'localhost',
-        (error) => {
+        error => {
           if (error != null) {
             throw error
           }
@@ -58,7 +58,7 @@ module.exports = {
         }
       )
     })
-  }
+  },
 }
 function __guard__(value, transform) {
   return typeof value !== 'undefined' && value !== null
diff --git a/services/track-changes/test/acceptance/js/helpers/TrackChangesClient.js b/services/track-changes/test/acceptance/js/helpers/TrackChangesClient.js
index a48ccc7a78..0216c2c928 100644
--- a/services/track-changes/test/acceptance/js/helpers/TrackChangesClient.js
+++ b/services/track-changes/test/acceptance/js/helpers/TrackChangesClient.js
@@ -28,7 +28,7 @@ const s3 = new aws.S3({
   accessKeyId: Settings.trackchanges.s3.key,
   secretAccessKey: Settings.trackchanges.s3.secret,
   endpoint: Settings.trackchanges.s3.endpoint,
-  s3ForcePathStyle: Settings.trackchanges.s3.pathStyle
+  s3ForcePathStyle: Settings.trackchanges.s3.pathStyle,
 })
 const S3_BUCKET = Settings.trackchanges.stores.doc_history
 
@@ -37,7 +37,7 @@ module.exports = TrackChangesClient = {
     if (callback == null) {
       callback = function (error, updates) {}
     }
-    return TrackChangesClient.flushDoc(project_id, doc_id, (error) => {
+    return TrackChangesClient.flushDoc(project_id, doc_id, error => {
       if (error != null) {
         return callback(error)
       }
@@ -51,7 +51,7 @@ module.exports = TrackChangesClient = {
     }
     return request.post(
       {
-        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/flush`
+        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/flush`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(204)
@@ -66,7 +66,7 @@ module.exports = TrackChangesClient = {
     }
     return request.post(
       {
-        url: `http://localhost:3015/project/${project_id}/flush`
+        url: `http://localhost:3015/project/${project_id}/flush`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(204)
@@ -91,7 +91,7 @@ module.exports = TrackChangesClient = {
     }
     return db.projectHistoryMetaData.findOne(
       {
-        project_id: ObjectId(project_id)
+        project_id: ObjectId(project_id),
       },
       callback
     )
@@ -103,13 +103,13 @@ module.exports = TrackChangesClient = {
     }
     return db.projectHistoryMetaData.updateOne(
       {
-        project_id: ObjectId(project_id)
+        project_id: ObjectId(project_id),
       },
       {
-        $set: { preserveHistory: true }
+        $set: { preserveHistory: true },
       },
       {
-        upsert: true
+        upsert: true,
       },
       callback
     )
@@ -122,13 +122,13 @@ module.exports = TrackChangesClient = {
     return rclient.sadd(
       Keys.docsWithHistoryOps({ project_id }),
       doc_id,
-      (error) => {
+      error => {
         if (error != null) {
           return callback(error)
         }
         return rclient.rpush(
           Keys.uncompressedHistoryOps({ doc_id }),
-          ...Array.from(Array.from(updates).map((u) => JSON.stringify(u))),
+          ...Array.from(Array.from(updates).map(u => JSON.stringify(u))),
           callback
         )
       }
@@ -141,7 +141,7 @@ module.exports = TrackChangesClient = {
     }
     return request.get(
       {
-        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/diff?from=${from}&to=${to}`
+        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/diff?from=${from}&to=${to}`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(200)
@@ -156,7 +156,7 @@ module.exports = TrackChangesClient = {
     }
     return request.get(
       {
-        url: `http://localhost:3015/project/${project_id}/updates?before=${options.before}&min_count=${options.min_count}`
+        url: `http://localhost:3015/project/${project_id}/updates?before=${options.before}&min_count=${options.min_count}`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(200)
@@ -184,8 +184,8 @@ module.exports = TrackChangesClient = {
       {
         url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/version/${version}/restore`,
         headers: {
-          'X-User-Id': user_id
-        }
+          'X-User-Id': user_id,
+        },
       },
       (error, response, body) => {
         response.statusCode.should.equal(204)
@@ -200,7 +200,7 @@ module.exports = TrackChangesClient = {
     }
     return request.post(
       {
-        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/push`
+        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/push`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(204)
@@ -215,7 +215,7 @@ module.exports = TrackChangesClient = {
     }
     return request.post(
       {
-        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/pull`
+        url: `http://localhost:3015/project/${project_id}/doc/${doc_id}/pull`,
       },
       (error, response, body) => {
         response.statusCode.should.equal(204)
@@ -254,7 +254,7 @@ module.exports = TrackChangesClient = {
     }
     const params = {
       Bucket: S3_BUCKET,
-      Key: `${project_id}/changes-${doc_id}/pack-${pack_id}`
+      Key: `${project_id}/changes-${doc_id}/pack-${pack_id}`,
     }
 
     return s3.getObject(params, (error, data) => {
@@ -280,7 +280,7 @@ module.exports = TrackChangesClient = {
     }
     let params = {
       Bucket: S3_BUCKET,
-      Prefix: `${project_id}/changes-${doc_id}`
+      Prefix: `${project_id}/changes-${doc_id}`,
     }
 
     return s3.listObjects(params, (error, data) => {
@@ -291,11 +291,11 @@ module.exports = TrackChangesClient = {
       params = {
         Bucket: S3_BUCKET,
         Delete: {
-          Objects: data.Contents.map((s3object) => ({ Key: s3object.Key }))
-        }
+          Objects: data.Contents.map(s3object => ({ Key: s3object.Key })),
+        },
       }
 
       return s3.deleteObjects(params, callback)
     })
-  }
+  },
 }
diff --git a/services/track-changes/test/setup.js b/services/track-changes/test/setup.js
index 9ebe599cea..17e1782172 100644
--- a/services/track-changes/test/setup.js
+++ b/services/track-changes/test/setup.js
@@ -14,8 +14,8 @@ SandboxedModule.configure({
       warn() {},
       err() {},
       error() {},
-      fatal() {}
-    }
+      fatal() {},
+    },
   },
-  globals: { Buffer, JSON, console, process }
+  globals: { Buffer, JSON, console, process },
 })
diff --git a/services/track-changes/test/unit/js/DiffGenerator/DiffGeneratorTests.js b/services/track-changes/test/unit/js/DiffGenerator/DiffGeneratorTests.js
index 75a8ab2c0f..2b67220de9 100644
--- a/services/track-changes/test/unit/js/DiffGenerator/DiffGeneratorTests.js
+++ b/services/track-changes/test/unit/js/DiffGenerator/DiffGeneratorTests.js
@@ -24,7 +24,7 @@ describe('DiffGenerator', function () {
     return (this.meta = {
       start_ts: this.ts,
       end_ts: this.ts,
-      user_id: this.user_id
+      user_id: this.user_id,
     })
   })
 
@@ -34,7 +34,7 @@ describe('DiffGenerator', function () {
         const content = 'hello world'
         const rewoundContent = this.DiffGenerator.rewindOp(content, {
           p: 6,
-          i: 'wo'
+          i: 'wo',
         })
         return rewoundContent.should.equal('hello rld')
       })
@@ -45,7 +45,7 @@ describe('DiffGenerator', function () {
         const content = 'hello rld'
         const rewoundContent = this.DiffGenerator.rewindOp(content, {
           p: 6,
-          d: 'wo'
+          d: 'wo',
         })
         return rewoundContent.should.equal('hello world')
       })
@@ -65,7 +65,7 @@ describe('DiffGenerator', function () {
         const content = 'foobar'
         const rewoundContent = this.DiffGenerator.rewindOp(content, {
           p: 4,
-          i: 'bar'
+          i: 'bar',
         })
         return rewoundContent.should.equal('foo')
       })
@@ -78,8 +78,8 @@ describe('DiffGenerator', function () {
       const update = {
         op: [
           { p: 3, i: 'bbb' },
-          { p: 6, i: 'ccc' }
-        ]
+          { p: 6, i: 'ccc' },
+        ],
       }
       const rewoundContent = this.DiffGenerator.rewindUpdate(content, update)
       return rewoundContent.should.equal('aaa')
@@ -91,7 +91,7 @@ describe('DiffGenerator', function () {
       const content = 'aaabbbccc'
       const updates = [
         { op: [{ p: 3, i: 'bbb' }] },
-        { op: [{ p: 6, i: 'ccc' }] }
+        { op: [{ p: 6, i: 'ccc' }] },
       ]
       const rewoundContent = this.DiffGenerator.rewindUpdates(content, updates)
       return rewoundContent.should.equal('aaa')
@@ -105,7 +105,7 @@ describe('DiffGenerator', function () {
       this.updates = [
         { i: 'mock-update-1' },
         { i: 'mock-update-2' },
-        { i: 'mock-update-3' }
+        { i: 'mock-update-3' },
       ]
       this.DiffGenerator.applyUpdateToDiff = sinon.stub().returns(this.diff)
       this.DiffGenerator.compressDiff = sinon.stub().returns(this.diff)
@@ -124,8 +124,8 @@ describe('DiffGenerator', function () {
         .calledWith(
           [
             {
-              u: this.content
-            }
+              u: this.content,
+            },
           ],
           this.updates[0]
         )
@@ -133,7 +133,7 @@ describe('DiffGenerator', function () {
     })
 
     it('should apply each update', function () {
-      return Array.from(this.updates).map((update) =>
+      return Array.from(this.updates).map(update =>
         this.DiffGenerator.applyUpdateToDiff
           .calledWith(sinon.match.any, update)
           .should.equal(true)
@@ -153,18 +153,18 @@ describe('DiffGenerator', function () {
         const diff = this.DiffGenerator.compressDiff([
           {
             i: 'foo',
-            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } }
+            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } },
           },
           {
             i: 'bar',
-            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id } }
-          }
+            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id } },
+          },
         ])
         return expect(diff).to.deep.equal([
           {
             i: 'foobar',
-            meta: { start_ts: 5, end_ts: 20, user: { id: this.user_id } }
-          }
+            meta: { start_ts: 5, end_ts: 20, user: { id: this.user_id } },
+          },
         ])
       })
     })
@@ -174,12 +174,12 @@ describe('DiffGenerator', function () {
         const input = [
           {
             i: 'foo',
-            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } }
+            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } },
           },
           {
             i: 'bar',
-            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id_2 } }
-          }
+            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id_2 } },
+          },
         ]
         const output = this.DiffGenerator.compressDiff(input)
         return expect(output).to.deep.equal(input)
@@ -191,18 +191,18 @@ describe('DiffGenerator', function () {
         const diff = this.DiffGenerator.compressDiff([
           {
             d: 'foo',
-            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } }
+            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } },
           },
           {
             d: 'bar',
-            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id } }
-          }
+            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id } },
+          },
         ])
         return expect(diff).to.deep.equal([
           {
             d: 'foobar',
-            meta: { start_ts: 5, end_ts: 20, user: { id: this.user_id } }
-          }
+            meta: { start_ts: 5, end_ts: 20, user: { id: this.user_id } },
+          },
         ])
       })
     })
@@ -212,12 +212,12 @@ describe('DiffGenerator', function () {
         const input = [
           {
             d: 'foo',
-            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } }
+            meta: { start_ts: 10, end_ts: 20, user: { id: this.user_id } },
           },
           {
             d: 'bar',
-            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id_2 } }
-          }
+            meta: { start_ts: 5, end_ts: 15, user: { id: this.user_id_2 } },
+          },
         ]
         const output = this.DiffGenerator.compressDiff(input)
         return expect(output).to.deep.equal(input)
@@ -230,34 +230,34 @@ describe('DiffGenerator', function () {
       it('should insert into the middle of (u)nchanged text', function () {
         const diff = this.DiffGenerator.applyUpdateToDiff([{ u: 'foobar' }], {
           op: [{ p: 3, i: 'baz' }],
-          meta: this.meta
+          meta: this.meta,
         })
         return expect(diff).to.deep.equal([
           { u: 'foo' },
           { i: 'baz', meta: this.meta },
-          { u: 'bar' }
+          { u: 'bar' },
         ])
       })
 
       it('should insert into the start of (u)changed text', function () {
         const diff = this.DiffGenerator.applyUpdateToDiff([{ u: 'foobar' }], {
           op: [{ p: 0, i: 'baz' }],
-          meta: this.meta
+          meta: this.meta,
         })
         return expect(diff).to.deep.equal([
           { i: 'baz', meta: this.meta },
-          { u: 'foobar' }
+          { u: 'foobar' },
         ])
       })
 
       it('should insert into the end of (u)changed text', function () {
         const diff = this.DiffGenerator.applyUpdateToDiff([{ u: 'foobar' }], {
           op: [{ p: 6, i: 'baz' }],
-          meta: this.meta
+          meta: this.meta,
         })
         return expect(diff).to.deep.equal([
           { u: 'foobar' },
-          { i: 'baz', meta: this.meta }
+          { i: 'baz', meta: this.meta },
         ])
       })
 
@@ -269,7 +269,7 @@ describe('DiffGenerator', function () {
         return expect(diff).to.deep.equal([
           { i: 'foo', meta: this.meta },
           { i: 'baz', meta: this.meta },
-          { i: 'bar', meta: this.meta }
+          { i: 'bar', meta: this.meta },
         ])
       })
 
@@ -282,7 +282,7 @@ describe('DiffGenerator', function () {
           { d: 'deleted', meta: this.meta },
           { u: 'foo' },
           { i: 'baz', meta: this.meta },
-          { u: 'bar' }
+          { u: 'bar' },
         ])
       })
     })
@@ -297,7 +297,7 @@ describe('DiffGenerator', function () {
           return expect(diff).to.deep.equal([
             { u: 'foo' },
             { d: 'baz', meta: this.meta },
-            { u: 'bar' }
+            { u: 'bar' },
           ])
         })
 
@@ -308,7 +308,7 @@ describe('DiffGenerator', function () {
           )
           return expect(diff).to.deep.equal([
             { d: 'foo', meta: this.meta },
-            { u: 'bazbar' }
+            { u: 'bazbar' },
           ])
         })
 
@@ -319,7 +319,7 @@ describe('DiffGenerator', function () {
           )
           return expect(diff).to.deep.equal([
             { u: 'foobaz' },
-            { d: 'bar', meta: this.meta }
+            { d: 'bar', meta: this.meta },
           ])
         })
 
@@ -333,7 +333,7 @@ describe('DiffGenerator', function () {
             { d: 'o', meta: this.meta },
             { d: 'baz', meta: this.meta },
             { d: 'b', meta: this.meta },
-            { u: 'ar' }
+            { u: 'ar' },
           ])
         })
       })
@@ -346,7 +346,7 @@ describe('DiffGenerator', function () {
           )
           return expect(diff).to.deep.equal([
             { i: 'foo', meta: this.meta },
-            { i: 'bar', meta: this.meta }
+            { i: 'bar', meta: this.meta },
           ])
         })
 
@@ -375,7 +375,7 @@ describe('DiffGenerator', function () {
             { u: 'fo' },
             { d: 'o', meta: this.meta },
             { d: 'b', meta: this.meta },
-            { u: 'ar' }
+            { u: 'ar' },
           ])
         })
       })
@@ -391,7 +391,7 @@ describe('DiffGenerator', function () {
             { d: 'o', meta: this.meta },
             { d: 'baz', meta: this.meta },
             { d: 'b', meta: this.meta },
-            { u: 'ar' }
+            { u: 'ar' },
           ])
         })
       })
@@ -401,7 +401,7 @@ describe('DiffGenerator', function () {
           return expect(() =>
             this.DiffGenerator.applyUpdateToDiff([{ u: 'foobazbar' }], {
               op: [{ p: 3, d: 'xxx' }],
-              meta: this.meta
+              meta: this.meta,
             })
           ).to.throw(this.DiffGenerator.ConsistencyError)
         })
@@ -410,7 +410,7 @@ describe('DiffGenerator', function () {
           return expect(() =>
             this.DiffGenerator.applyUpdateToDiff([{ u: 'foobazbar' }], {
               op: [{ p: 0, d: 'xxx' }],
-              meta: this.meta
+              meta: this.meta,
             })
           ).to.throw(this.DiffGenerator.ConsistencyError)
         })
@@ -419,7 +419,7 @@ describe('DiffGenerator', function () {
           return expect(() =>
             this.DiffGenerator.applyUpdateToDiff([{ u: 'foobazbar' }], {
               op: [{ p: 6, d: 'xxx' }],
-              meta: this.meta
+              meta: this.meta,
             })
           ).to.throw(this.DiffGenerator.ConsistencyError)
         })
@@ -434,7 +434,7 @@ describe('DiffGenerator', function () {
           return expect(diff).to.deep.equal([
             { u: 'foo' },
             { i: 'baz', meta: this.meta },
-            { d: 'bar', meta: this.meta }
+            { d: 'bar', meta: this.meta },
           ])
         })
       })
@@ -447,7 +447,7 @@ describe('DiffGenerator', function () {
           )
           return expect(diff).to.deep.equal([
             { d: 'bar', meta: this.meta },
-            { i: 'baz', meta: this.meta }
+            { i: 'baz', meta: this.meta },
           ])
         })
       })
diff --git a/services/track-changes/test/unit/js/DiffManager/DiffManagerTests.js b/services/track-changes/test/unit/js/DiffManager/DiffManagerTests.js
index b2f4ec6a59..846ad706c2 100644
--- a/services/track-changes/test/unit/js/DiffManager/DiffManagerTests.js
+++ b/services/track-changes/test/unit/js/DiffManager/DiffManagerTests.js
@@ -21,8 +21,8 @@ describe('DiffManager', function () {
       requires: {
         './UpdatesManager': (this.UpdatesManager = {}),
         './DocumentUpdaterManager': (this.DocumentUpdaterManager = {}),
-        './DiffGenerator': (this.DiffGenerator = {})
-      }
+        './DiffGenerator': (this.DiffGenerator = {}),
+      },
     })
     this.callback = sinon.stub()
     this.from = new Date()
@@ -114,23 +114,23 @@ describe('DiffManager', function () {
         {
           op: 'mock-4',
           v: 42,
-          meta: { start_ts: new Date(this.to.getTime() + 20) }
+          meta: { start_ts: new Date(this.to.getTime() + 20) },
         },
         {
           op: 'mock-3',
           v: 41,
-          meta: { start_ts: new Date(this.to.getTime() + 10) }
+          meta: { start_ts: new Date(this.to.getTime() + 10) },
         },
         {
           op: 'mock-2',
           v: 40,
-          meta: { start_ts: new Date(this.to.getTime() - 10) }
+          meta: { start_ts: new Date(this.to.getTime() - 10) },
         },
         {
           op: 'mock-1',
           v: 39,
-          meta: { start_ts: new Date(this.to.getTime() - 20) }
-        }
+          meta: { start_ts: new Date(this.to.getTime() - 20) },
+        },
       ]
       this.fromVersion = 39
       this.toVersion = 40
@@ -333,23 +333,23 @@ describe('DiffManager', function () {
         {
           op: 'mock-4',
           v: 42,
-          meta: { start_ts: new Date(this.to.getTime() + 20) }
+          meta: { start_ts: new Date(this.to.getTime() + 20) },
         },
         {
           op: 'mock-3',
           v: 41,
-          meta: { start_ts: new Date(this.to.getTime() + 10) }
+          meta: { start_ts: new Date(this.to.getTime() + 10) },
         },
         {
           op: 'mock-2',
           v: 40,
-          meta: { start_ts: new Date(this.to.getTime() - 10) }
+          meta: { start_ts: new Date(this.to.getTime() - 10) },
         },
         {
           op: 'mock-1',
           v: 39,
-          meta: { start_ts: new Date(this.to.getTime() - 20) }
-        }
+          meta: { start_ts: new Date(this.to.getTime() - 20) },
+        },
       ]
       this.fromVersion = 39
       this.rewound_content = 'rewound-content'
@@ -400,7 +400,7 @@ describe('DiffManager', function () {
         this.version = 50
         this.updates = [
           { op: 'mock-1', v: 40 },
-          { op: 'mock-1', v: 39 }
+          { op: 'mock-1', v: 39 },
         ]
         this.DiffManager.getLatestDocAndUpdates = sinon
           .stub()
diff --git a/services/track-changes/test/unit/js/DocArchive/MongoAWS.js b/services/track-changes/test/unit/js/DocArchive/MongoAWS.js
index cc539c8393..72bcaccddf 100644
--- a/services/track-changes/test/unit/js/DocArchive/MongoAWS.js
+++ b/services/track-changes/test/unit/js/DocArchive/MongoAWS.js
@@ -25,12 +25,12 @@ describe('MongoAWS', function () {
           trackchanges: {
             s3: {
               secret: 's3-secret',
-              key: 's3-key'
+              key: 's3-key',
             },
             stores: {
-              doc_history: 's3-bucket'
-            }
-          }
+              doc_history: 's3-bucket',
+            },
+          },
         }),
         child_process: (this.child_process = {}),
         'mongo-uri': (this.mongouri = {}),
@@ -40,8 +40,8 @@ describe('MongoAWS', function () {
         './mongodb': { db: (this.db = {}), ObjectId },
         JSONStream: (this.JSONStream = {}),
         'readline-stream': (this.readline = sinon.stub()),
-        '@overleaf/metrics': { inc() {} }
-      }
+        '@overleaf/metrics': { inc() {} },
+      },
     })
 
     this.project_id = ObjectId().toString()
diff --git a/services/track-changes/test/unit/js/DocumentUpdaterManager/DocumentUpdaterManagerTests.js b/services/track-changes/test/unit/js/DocumentUpdaterManager/DocumentUpdaterManagerTests.js
index c8a218d2a3..8221f98d06 100644
--- a/services/track-changes/test/unit/js/DocumentUpdaterManager/DocumentUpdaterManagerTests.js
+++ b/services/track-changes/test/unit/js/DocumentUpdaterManager/DocumentUpdaterManagerTests.js
@@ -20,9 +20,9 @@ describe('DocumentUpdaterManager', function () {
       requires: {
         request: (this.request = {}),
         '@overleaf/settings': (this.settings = {
-          apis: { documentupdater: { url: 'http://example.com' } }
-        })
-      }
+          apis: { documentupdater: { url: 'http://example.com' } },
+        }),
+      },
     })
     this.callback = sinon.stub()
     this.lines = ['one', 'two', 'three']
@@ -35,7 +35,7 @@ describe('DocumentUpdaterManager', function () {
         this.body = JSON.stringify({
           lines: this.lines,
           version: this.version,
-          ops: []
+          ops: [],
         })
         this.request.get = sinon
           .stub()
@@ -135,8 +135,8 @@ describe('DocumentUpdaterManager', function () {
               lines: this.content.split('\n'),
               source: 'restore',
               user_id: this.user_id,
-              undoing: true
-            }
+              undoing: true,
+            },
           })
           .should.equal(true)
       })
diff --git a/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js b/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
index 9746213922..6b82dd2b80 100644
--- a/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
+++ b/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
@@ -24,8 +24,8 @@ describe('HttpController', function () {
         './RestoreManager': (this.RestoreManager = {}),
         './PackManager': (this.PackManager = {}),
         './DocArchiveManager': (this.DocArchiveManager = {}),
-        './HealthChecker': (this.HealthChecker = {})
-      }
+        './HealthChecker': (this.HealthChecker = {}),
+      },
     })
     this.doc_id = 'doc-id-123'
     this.project_id = 'project-id-123'
@@ -39,8 +39,8 @@ describe('HttpController', function () {
       this.req = {
         params: {
           doc_id: this.doc_id,
-          project_id: this.project_id
-        }
+          project_id: this.project_id,
+        },
       }
       this.res = { sendStatus: sinon.stub() }
       this.UpdatesManager.processUncompressedUpdatesWithLock = sinon
@@ -64,8 +64,8 @@ describe('HttpController', function () {
     beforeEach(function () {
       this.req = {
         params: {
-          project_id: this.project_id
-        }
+          project_id: this.project_id,
+        },
       }
       this.res = { sendStatus: sinon.stub() }
       this.UpdatesManager.processUncompressedUpdatesForProject = sinon
@@ -92,12 +92,12 @@ describe('HttpController', function () {
       this.req = {
         params: {
           doc_id: this.doc_id,
-          project_id: this.project_id
+          project_id: this.project_id,
         },
         query: {
           from: this.from.toString(),
-          to: this.to.toString()
-        }
+          to: this.to.toString(),
+        },
       }
       this.res = { json: sinon.stub() }
       this.diff = [{ u: 'mock-diff' }]
@@ -128,12 +128,12 @@ describe('HttpController', function () {
       this.min_count = 10
       this.req = {
         params: {
-          project_id: this.project_id
+          project_id: this.project_id,
         },
         query: {
           before: this.before.toString(),
-          min_count: this.min_count.toString()
-        }
+          min_count: this.min_count.toString(),
+        },
       }
       this.res = { json: sinon.stub() }
       this.updates = ['mock-summarized-updates']
@@ -147,7 +147,7 @@ describe('HttpController', function () {
       return this.UpdatesManager.getSummarizedProjectUpdates
         .calledWith(this.project_id, {
           before: this.before,
-          min_count: this.min_count
+          min_count: this.min_count,
         })
         .should.equal(true)
     })
@@ -156,7 +156,7 @@ describe('HttpController', function () {
       return this.res.json
         .calledWith({
           updates: this.updates,
-          nextBeforeTimestamp: this.nextBeforeTimestamp
+          nextBeforeTimestamp: this.nextBeforeTimestamp,
         })
         .should.equal(true)
     })
@@ -169,11 +169,11 @@ describe('HttpController', function () {
         params: {
           doc_id: this.doc_id,
           project_id: this.project_id,
-          version: this.version
+          version: this.version,
         },
         headers: {
-          'x-user-id': this.user_id
-        }
+          'x-user-id': this.user_id,
+        },
       }
       this.res = { sendStatus: sinon.stub() }
 
diff --git a/services/track-changes/test/unit/js/LockManager/LockManagerTests.js b/services/track-changes/test/unit/js/LockManager/LockManagerTests.js
index 1c933c3eea..fd76bc0d2d 100644
--- a/services/track-changes/test/unit/js/LockManager/LockManagerTests.js
+++ b/services/track-changes/test/unit/js/LockManager/LockManagerTests.js
@@ -24,18 +24,18 @@ describe('LockManager', function () {
   beforeEach(function () {
     this.Settings = {
       redis: {
-        lock: {}
-      }
+        lock: {},
+      },
     }
     this.LockManager = SandboxedModule.require(modulePath, {
       requires: {
         '@overleaf/redis-wrapper': {
           createClient: () => {
             return (this.rclient = { auth: sinon.stub() })
-          }
+          },
         },
-        '@overleaf/settings': this.Settings
-      }
+        '@overleaf/settings': this.Settings,
+      },
     })
 
     this.key = 'lock-key'
@@ -240,7 +240,7 @@ describe('LockManager', function () {
     describe('when the runner function returns an error', function () {
       beforeEach(function () {
         this.error = new Error('oops')
-        this.runner = (releaseLock) => {
+        this.runner = releaseLock => {
           if (releaseLock == null) {
             releaseLock = function (error) {}
           }
diff --git a/services/track-changes/test/unit/js/MongoManager/MongoManagerTests.js b/services/track-changes/test/unit/js/MongoManager/MongoManagerTests.js
index d96b27d8d0..6e560e7ab8 100644
--- a/services/track-changes/test/unit/js/MongoManager/MongoManagerTests.js
+++ b/services/track-changes/test/unit/js/MongoManager/MongoManagerTests.js
@@ -24,8 +24,8 @@ describe('MongoManager', function () {
       requires: {
         './mongodb': { db: (this.db = {}), ObjectId },
         './PackManager': (this.PackManager = {}),
-        '@overleaf/metrics': { timeAsyncMethod() {} }
-      }
+        '@overleaf/metrics': { timeAsyncMethod() {} },
+      },
     })
     this.callback = sinon.stub()
     this.doc_id = ObjectId().toString()
@@ -166,10 +166,10 @@ describe('MongoManager', function () {
         .calledWith(
           {
             doc_id: ObjectId(this.doc_id),
-            project_id: { $exists: false }
+            project_id: { $exists: false },
           },
           {
-            $set: { project_id: ObjectId(this.project_id) }
+            $set: { project_id: ObjectId(this.project_id) },
           }
         )
         .should.equal(true)
@@ -184,7 +184,7 @@ describe('MongoManager', function () {
     beforeEach(function () {
       this.metadata = { mock: 'metadata' }
       this.db.projectHistoryMetaData = {
-        findOne: sinon.stub().callsArgWith(1, null, this.metadata)
+        findOne: sinon.stub().callsArgWith(1, null, this.metadata),
       }
       return this.MongoManager.getProjectMetaData(
         this.project_id,
@@ -207,7 +207,7 @@ describe('MongoManager', function () {
     beforeEach(function () {
       this.metadata = { mock: 'metadata' }
       this.db.projectHistoryMetaData = {
-        updateOne: sinon.stub().yields()
+        updateOne: sinon.stub().yields(),
       }
       return this.MongoManager.setProjectMetaData(
         this.project_id,
@@ -220,13 +220,13 @@ describe('MongoManager', function () {
       return this.db.projectHistoryMetaData.updateOne
         .calledWith(
           {
-            project_id: ObjectId(this.project_id)
+            project_id: ObjectId(this.project_id),
           },
           {
-            $set: this.metadata
+            $set: this.metadata,
           },
           {
-            upsert: true
+            upsert: true,
           }
         )
         .should.equal(true)
diff --git a/services/track-changes/test/unit/js/PackManager/PackManagerTests.js b/services/track-changes/test/unit/js/PackManager/PackManagerTests.js
index 1f85dcf38c..4f538f2109 100644
--- a/services/track-changes/test/unit/js/PackManager/PackManagerTests.js
+++ b/services/track-changes/test/unit/js/PackManager/PackManagerTests.js
@@ -31,9 +31,9 @@ describe('PackManager', function () {
         '@overleaf/metrics': { inc() {} },
         './ProjectIterator': require('../../../../app/js/ProjectIterator.js'), // Cache for speed
         '@overleaf/settings': {
-          redis: { lock: { key_schema: {} } }
-        }
-      }
+          redis: { lock: { key_schema: {} } },
+        },
+      },
     })
     this.callback = sinon.stub()
     this.doc_id = ObjectId().toString()
@@ -51,20 +51,20 @@ describe('PackManager', function () {
         _id: '12345',
         pack: [
           { op: 'op-1', meta: 'meta-1', v: 1 },
-          { op: 'op-2', meta: 'meta-2', v: 2 }
+          { op: 'op-2', meta: 'meta-2', v: 2 },
         ],
         n: 2,
-        sz: 100
+        sz: 100,
       }
       this.newUpdates = [
         { op: 'op-3', meta: 'meta-3', v: 3 },
-        { op: 'op-4', meta: 'meta-4', v: 4 }
+        { op: 'op-4', meta: 'meta-4', v: 4 },
       ]
       return (this.db.docHistory = {
         insertOne: sinon.stub().yields(),
         insert: sinon.stub().callsArg(1),
         updateOne: sinon.stub().yields(),
-        findAndModify: sinon.stub().callsArg(1)
+        findAndModify: sinon.stub().callsArg(1),
       })
     })
 
@@ -95,10 +95,10 @@ describe('PackManager', function () {
 
       return describe('for many small updates', function () {
         beforeEach(function () {
-          this.newUpdates = __range__(0, 2048, true).map((i) => ({
+          this.newUpdates = __range__(0, 2048, true).map(i => ({
             op: `op-${i}`,
             meta: `meta-${i}`,
-            v: i
+            v: i,
           }))
           return this.PackManager.insertCompressedUpdates(
             this.project_id,
@@ -209,10 +209,10 @@ describe('PackManager', function () {
 
       describe('for many small updates', function () {
         beforeEach(function () {
-          this.newUpdates = __range__(0, 2048, true).map((i) => ({
+          this.newUpdates = __range__(0, 2048, true).map(i => ({
             op: `op-${i}`,
             meta: `meta-${i}`,
-            v: i
+            v: i,
           }))
           return this.PackManager.insertCompressedUpdates(
             this.project_id,
@@ -292,12 +292,12 @@ describe('PackManager', function () {
             0.75 * this.PackManager.MAX_SIZE,
             true
           )
-            .map((j) => 'a')
+            .map(j => 'a')
             .join('')
-          this.newUpdates = [0, 1, 2, 3, 4].map((i) => ({
+          this.newUpdates = [0, 1, 2, 3, 4].map(i => ({
             op: `op-${i}-${longString}`,
             meta: `meta-${i}`,
-            v: i
+            v: i,
           }))
           return this.PackManager.insertCompressedUpdates(
             this.project_id,
@@ -393,7 +393,7 @@ describe('PackManager', function () {
                 doc_id: ObjectId(this.doc_id),
                 n: this.newUpdates.length,
                 v: this.newUpdates[0].v,
-                v_end: this.newUpdates[this.newUpdates.length - 1].v
+                v_end: this.newUpdates[this.newUpdates.length - 1].v,
               })
               .should.equal(true)
           })
@@ -401,7 +401,7 @@ describe('PackManager', function () {
           it('should set an expiry time in the future', function () {
             return this.db.docHistory.insertOne
               .calledWithMatch({
-                expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000)
+                expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000),
               })
               .should.equal(true)
           })
@@ -419,12 +419,12 @@ describe('PackManager', function () {
           _id: '12345',
           pack: [
             { op: 'op-1', meta: 'meta-1', v: 1 },
-            { op: 'op-2', meta: 'meta-2', v: 2 }
+            { op: 'op-2', meta: 'meta-2', v: 2 },
           ],
           n: 2,
           sz: 100,
           meta: { start_ts: Date.now() - 6 * 3600 * 1000 },
-          expiresAt: new Date(Date.now())
+          expiresAt: new Date(Date.now()),
         }
 
         return this.PackManager.flushCompressedUpdates(
@@ -444,7 +444,7 @@ describe('PackManager', function () {
               { _id: this.lastUpdate._id },
               {
                 $push: { pack: { $each: this.newUpdates } },
-                $set: { v_end: this.newUpdates[this.newUpdates.length - 1].v }
+                $set: { v_end: this.newUpdates[this.newUpdates.length - 1].v },
               }
             )
             .should.equal(true)
@@ -453,7 +453,7 @@ describe('PackManager', function () {
         it('should set an expiry time in the future', function () {
           return this.db.docHistory.updateOne
             .calledWithMatch(sinon.match.any, {
-              $set: { expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000) }
+              $set: { expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000) },
             })
             .should.equal(true)
         })
@@ -472,12 +472,12 @@ describe('PackManager', function () {
           _id: '12345',
           pack: [
             { op: 'op-1', meta: 'meta-1', v: 1 },
-            { op: 'op-2', meta: 'meta-2', v: 2 }
+            { op: 'op-2', meta: 'meta-2', v: 2 },
           ],
           n: 2,
           sz: 100,
           meta: { start_ts: Date.now() - 6 * 3600 * 1000 },
-          expiresAt: new Date(Date.now())
+          expiresAt: new Date(Date.now()),
         }
 
         return this.PackManager.flushCompressedUpdates(
@@ -499,7 +499,7 @@ describe('PackManager', function () {
               doc_id: ObjectId(this.doc_id),
               n: this.newUpdates.length,
               v: this.newUpdates[0].v,
-              v_end: this.newUpdates[this.newUpdates.length - 1].v
+              v_end: this.newUpdates[this.newUpdates.length - 1].v,
             })
             .should.equal(true)
         })
@@ -522,12 +522,12 @@ describe('PackManager', function () {
           _id: '12345',
           pack: [
             { op: 'op-1', meta: 'meta-1', v: 1 },
-            { op: 'op-2', meta: 'meta-2', v: 2 }
+            { op: 'op-2', meta: 'meta-2', v: 2 },
           ],
           n: 2,
           sz: 100,
           meta: { start_ts: Date.now() - 30 * 24 * 3600 * 1000 },
-          expiresAt: new Date(Date.now() - 30 * 24 * 3600 * 1000)
+          expiresAt: new Date(Date.now() - 30 * 24 * 3600 * 1000),
         }
 
         return this.PackManager.flushCompressedUpdates(
@@ -549,7 +549,7 @@ describe('PackManager', function () {
               doc_id: ObjectId(this.doc_id),
               n: this.newUpdates.length,
               v: this.newUpdates[0].v,
-              v_end: this.newUpdates[this.newUpdates.length - 1].v
+              v_end: this.newUpdates[this.newUpdates.length - 1].v,
             })
             .should.equal(true)
         })
@@ -557,7 +557,7 @@ describe('PackManager', function () {
         it('should set an expiry time in the future', function () {
           return this.db.docHistory.insertOne
             .calledWithMatch({
-              expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000)
+              expiresAt: new Date(Date.now() + 7 * 24 * 3600 * 1000),
             })
             .should.equal(true)
         })
@@ -602,7 +602,7 @@ describe('PackManager', function () {
     describe('when an archive is in progress', function () {
       beforeEach(function () {
         this.db.docHistoryIndex = {
-          findOne: sinon.stub().callsArgWith(2, null, { inS3: false })
+          findOne: sinon.stub().callsArgWith(2, null, { inS3: false }),
         }
         return this.PackManager.checkArchiveNotInProgress(
           this.project_id,
@@ -624,7 +624,7 @@ describe('PackManager', function () {
     describe('when an archive is completed', function () {
       beforeEach(function () {
         this.db.docHistoryIndex = {
-          findOne: sinon.stub().callsArgWith(2, null, { inS3: true })
+          findOne: sinon.stub().callsArgWith(2, null, { inS3: true }),
         }
         return this.PackManager.checkArchiveNotInProgress(
           this.project_id,
@@ -646,7 +646,7 @@ describe('PackManager', function () {
     return describe('when the archive has not started or completed', function () {
       beforeEach(function () {
         this.db.docHistoryIndex = {
-          findOne: sinon.stub().callsArgWith(2, null, {})
+          findOne: sinon.stub().callsArgWith(2, null, {}),
         }
         return this.PackManager.checkArchiveNotInProgress(
           this.project_id,
diff --git a/services/track-changes/test/unit/js/RedisManager/RedisManagerTests.js b/services/track-changes/test/unit/js/RedisManager/RedisManagerTests.js
index 0196bc0ae2..f0c9b0f3d5 100644
--- a/services/track-changes/test/unit/js/RedisManager/RedisManagerTests.js
+++ b/services/track-changes/test/unit/js/RedisManager/RedisManagerTests.js
@@ -24,9 +24,9 @@ describe('RedisManager', function () {
           createClient: () => {
             return (this.rclient = {
               auth: sinon.stub(),
-              multi: () => this.rclient
+              multi: () => this.rclient,
             })
-          }
+          },
         },
         '@overleaf/settings': {
           redis: {
@@ -37,12 +37,12 @@ describe('RedisManager', function () {
                 },
                 docsWithHistoryOps({ project_id }) {
                   return `DocsWithHistoryOps:${project_id}`
-                }
-              }
-            }
-          }
-        }
-      }
+                },
+              },
+            },
+          },
+        },
+      },
     })
     this.doc_id = 'doc-id-123'
     this.project_id = 'project-id-123'
@@ -54,9 +54,9 @@ describe('RedisManager', function () {
     beforeEach(function () {
       this.rawUpdates = [
         { v: 42, op: 'mock-op-42' },
-        { v: 45, op: 'mock-op-45' }
+        { v: 45, op: 'mock-op-45' },
       ]
-      this.jsonUpdates = Array.from(this.rawUpdates).map((update) =>
+      this.jsonUpdates = Array.from(this.rawUpdates).map(update =>
         JSON.stringify(update)
       )
       this.rclient.lrange = sinon.stub().callsArgWith(3, null, this.jsonUpdates)
diff --git a/services/track-changes/test/unit/js/RestoreManager/RestoreManagerTests.js b/services/track-changes/test/unit/js/RestoreManager/RestoreManagerTests.js
index dd664a6003..9047946405 100644
--- a/services/track-changes/test/unit/js/RestoreManager/RestoreManagerTests.js
+++ b/services/track-changes/test/unit/js/RestoreManager/RestoreManagerTests.js
@@ -19,8 +19,8 @@ describe('RestoreManager', function () {
     this.RestoreManager = SandboxedModule.require(modulePath, {
       requires: {
         './DocumentUpdaterManager': (this.DocumentUpdaterManager = {}),
-        './DiffManager': (this.DiffManager = {})
-      }
+        './DiffManager': (this.DiffManager = {}),
+      },
     })
     this.callback = sinon.stub()
     this.project_id = 'mock-project-id'
diff --git a/services/track-changes/test/unit/js/UpdateCompressor/UpdateCompressorTests.js b/services/track-changes/test/unit/js/UpdateCompressor/UpdateCompressorTests.js
index a703ae8084..cd7c6c4b76 100644
--- a/services/track-changes/test/unit/js/UpdateCompressor/UpdateCompressorTests.js
+++ b/services/track-changes/test/unit/js/UpdateCompressor/UpdateCompressorTests.js
@@ -15,18 +15,18 @@ const modulePath = '../../../../app/js/UpdateCompressor.js'
 const SandboxedModule = require('sandboxed-module')
 
 const bigstring = __range__(0, 2 * 1024 * 1024, true)
-  .map((i) => 'a')
+  .map(i => 'a')
   .join('')
 const mediumstring = __range__(0, 1024 * 1024, true)
-  .map((j) => 'a')
+  .map(j => 'a')
   .join('')
 
 describe('UpdateCompressor', function () {
   beforeEach(function () {
     this.UpdateCompressor = SandboxedModule.require(modulePath, {
       requires: {
-        '../lib/diff_match_patch': require('../../../../app/lib/diff_match_patch')
-      }
+        '../lib/diff_match_patch': require('../../../../app/lib/diff_match_patch'),
+      },
     })
     this.user_id = 'user-id-1'
     this.other_user_id = 'user-id-2'
@@ -41,37 +41,37 @@ describe('UpdateCompressor', function () {
           {
             op: [
               (this.op1 = { p: 0, i: 'Foo' }),
-              (this.op2 = { p: 6, i: 'bar' })
+              (this.op2 = { p: 6, i: 'bar' }),
             ],
             meta: { ts: this.ts1, user_id: this.user_id },
-            v: 42
+            v: 42,
           },
           {
             op: [(this.op3 = { p: 10, i: 'baz' })],
             meta: { ts: this.ts2, user_id: this.other_user_id },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       ).to.deep.equal([
         {
           op: this.op1,
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
+          v: 42,
         },
         {
           op: this.op2,
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
+          v: 42,
         },
         {
           op: this.op3,
           meta: {
             start_ts: this.ts2,
             end_ts: this.ts2,
-            user_id: this.other_user_id
+            user_id: this.other_user_id,
           },
-          v: 43
-        }
+          v: 43,
+        },
       ])
     })
 
@@ -81,15 +81,15 @@ describe('UpdateCompressor', function () {
           {
             op: [],
             meta: { ts: this.ts1, user_id: this.user_id },
-            v: 42
-          }
+            v: 42,
+          },
         ])
       ).to.deep.equal([
         {
           op: this.UpdateCompressor.NOOP,
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
-        }
+          v: 42,
+        },
       ])
     })
 
@@ -100,23 +100,23 @@ describe('UpdateCompressor', function () {
             op: [
               (this.op1 = { p: 0, i: 'Foo' }),
               (this.op2 = { p: 9, c: 'baz' }),
-              (this.op3 = { p: 6, i: 'bar' })
+              (this.op3 = { p: 6, i: 'bar' }),
             ],
             meta: { ts: this.ts1, user_id: this.user_id },
-            v: 42
-          }
+            v: 42,
+          },
         ])
       ).to.deep.equal([
         {
           op: this.op1,
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
+          v: 42,
         },
         {
           op: this.op3,
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
-        }
+          v: 42,
+        },
       ])
     })
   })
@@ -130,44 +130,44 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: (this.op2 = { p: 6, i: 'bar' }),
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: (this.op3 = { p: 10, i: 'baz' }),
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.other_user_id
+              user_id: this.other_user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       ).to.deep.equal([
         {
           op: [this.op1, this.op2],
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
+          v: 42,
         },
         {
           op: [this.op3],
           meta: {
             start_ts: this.ts2,
             end_ts: this.ts2,
-            user_id: this.other_user_id
+            user_id: this.other_user_id,
           },
-          v: 43
-        }
+          v: 43,
+        },
       ])
     })
 
@@ -179,17 +179,17 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
-          }
+            v: 42,
+          },
         ])
       ).to.deep.equal([
         {
           op: [],
           meta: { start_ts: this.ts1, end_ts: this.ts1, user_id: this.user_id },
-          v: 42
-        }
+          v: 42,
+        },
       ])
     })
   })
@@ -202,13 +202,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 6, i: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -216,10 +216,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -229,13 +229,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 5, i: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -243,10 +243,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -256,13 +256,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 9, i: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -270,19 +270,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 9, i: 'bar' },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -292,13 +292,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 6, i: bigstring },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -306,19 +306,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 6, i: bigstring },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -328,13 +328,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: bigstring },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3 + bigstring.length, i: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -342,19 +342,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 3 + bigstring.length, i: 'bar' },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -364,13 +364,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: mediumstring },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3 + mediumstring.length, i: mediumstring },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -378,19 +378,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 3 + mediumstring.length, i: mediumstring },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -402,13 +402,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, d: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3, d: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -416,10 +416,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -429,13 +429,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, d: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 1, d: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -443,10 +443,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -456,13 +456,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, d: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 9, d: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -470,19 +470,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 9, d: 'bar' },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -494,13 +494,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 5, d: 'o' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -508,10 +508,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -521,13 +521,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'fobaro' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 5, d: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -535,10 +535,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -548,13 +548,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3, d: 'foo' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -562,10 +562,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -575,13 +575,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foo' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 9, d: 'bar' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -589,19 +589,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 9, d: 'bar' },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -611,13 +611,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, i: 'foobar' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 6, d: 'bardle' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -625,19 +625,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 6, d: 'bardle' },
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -649,13 +649,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, d: 'one two three four five six seven eight' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3, i: 'one 2 three four five six seven eight' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -663,19 +663,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
+            v: 43,
           },
           {
             op: { p: 7, i: '2' },
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
 
@@ -685,13 +685,13 @@ describe('UpdateCompressor', function () {
             {
               op: { p: 3, d: 'one two three four five six seven eight' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 3, i: 'one two three four five six seven eight' },
               meta: { ts: this.ts2, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -699,10 +699,10 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -714,13 +714,13 @@ describe('UpdateCompressor', function () {
             {
               op: this.UpdateCompressor.NOOP,
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 6, i: 'bar' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -728,19 +728,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 6, i: 'bar' },
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -752,13 +752,13 @@ describe('UpdateCompressor', function () {
             {
               op: this.UpdateCompressor.NOOP,
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 42
+              v: 42,
             },
             {
               op: { p: 6, d: 'bar' },
               meta: { ts: this.ts1, user_id: this.user_id },
-              v: 43
-            }
+              v: 43,
+            },
           ])
         ).to.deep.equal([
           {
@@ -766,19 +766,19 @@ describe('UpdateCompressor', function () {
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: { p: 6, d: 'bar' },
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
@@ -792,45 +792,45 @@ describe('UpdateCompressor', function () {
             {
               op: [
                 { p: 1000, d: 'hello' },
-                { p: 1000, i: 'HELLO()' }
+                { p: 1000, i: 'HELLO()' },
               ],
               meta: {
                 start_ts: this.ts1,
                 end_ts: this.ts1,
-                user_id: this.user_id
+                user_id: this.user_id,
               },
-              v: 42
+              v: 42,
             },
             [
               {
                 op: [{ p: 1006, i: 'WORLD' }],
                 meta: { ts: this.ts2, user_id: this.user_id },
-                v: 43
-              }
+                v: 43,
+              },
             ]
           )
         ).to.deep.equal([
           {
             op: [
               { p: 1000, d: 'hello' },
-              { p: 1000, i: 'HELLO()' }
+              { p: 1000, i: 'HELLO()' },
             ],
             meta: {
               start_ts: this.ts1,
               end_ts: this.ts1,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 42
+            v: 42,
           },
           {
             op: [{ p: 1006, i: 'WORLD' }],
             meta: {
               start_ts: this.ts2,
               end_ts: this.ts2,
-              user_id: this.user_id
+              user_id: this.user_id,
             },
-            v: 43
-          }
+            v: 43,
+          },
         ])
       })
     })
diff --git a/services/track-changes/test/unit/js/UpdateTrimmer/UpdateTrimmerTests.js b/services/track-changes/test/unit/js/UpdateTrimmer/UpdateTrimmerTests.js
index 2d89a3520d..a49554d9bb 100644
--- a/services/track-changes/test/unit/js/UpdateTrimmer/UpdateTrimmerTests.js
+++ b/services/track-changes/test/unit/js/UpdateTrimmer/UpdateTrimmerTests.js
@@ -23,8 +23,8 @@ describe('UpdateTrimmer', function () {
     this.UpdateTrimmer = SandboxedModule.require(modulePath, {
       requires: {
         './WebApiManager': (this.WebApiManager = {}),
-        './MongoManager': (this.MongoManager = {})
-      }
+        './MongoManager': (this.MongoManager = {}),
+      },
     })
 
     this.callback = sinon.stub()
diff --git a/services/track-changes/test/unit/js/UpdatesManager/UpdatesManagerTests.js b/services/track-changes/test/unit/js/UpdatesManager/UpdatesManagerTests.js
index 68904e9471..74233e6ffa 100644
--- a/services/track-changes/test/unit/js/UpdatesManager/UpdatesManagerTests.js
+++ b/services/track-changes/test/unit/js/UpdatesManager/UpdatesManagerTests.js
@@ -38,12 +38,12 @@ describe('UpdatesManager', function () {
               key_schema: {
                 historyLock({ doc_id }) {
                   return `HistoryLock:${doc_id}`
-                }
-              }
-            }
-          }
-        }
-      }
+                },
+              },
+            },
+          },
+        },
+      },
     })
     this.doc_id = 'doc-id-123'
     this.project_id = 'project-id-123'
@@ -79,7 +79,7 @@ describe('UpdatesManager', function () {
       beforeEach(function () {
         this.rawUpdates = [
           { v: 12, op: 'mock-op-12' },
-          { v: 13, op: 'mock-op-13' }
+          { v: 13, op: 'mock-op-13' },
         ]
         this.compressedUpdates = [{ v: 13, op: 'compressed-op-12' }]
 
@@ -127,7 +127,7 @@ describe('UpdatesManager', function () {
         this.lastCompressedUpdate = { v: 11, op: 'compressed-op-11' }
         this.compressedUpdates = [
           { v: 12, op: 'compressed-op-11+12' },
-          { v: 13, op: 'compressed-op-12' }
+          { v: 13, op: 'compressed-op-12' },
         ]
 
         this.MongoManager.peekLastCompressedUpdate = sinon
@@ -148,7 +148,7 @@ describe('UpdatesManager', function () {
         beforeEach(function () {
           this.rawUpdates = [
             { v: 12, op: 'mock-op-12' },
-            { v: 13, op: 'mock-op-13' }
+            { v: 13, op: 'mock-op-13' },
           ]
           return this.UpdatesManager.compressAndSaveRawUpdates(
             this.project_id,
@@ -192,11 +192,11 @@ describe('UpdatesManager', function () {
         beforeEach(function () {
           this.lastCompressedUpdate = {
             pack: [{ v: 11, op: 'compressed-op-11' }],
-            v: 11
+            v: 11,
           }
           this.rawUpdates = [
             { v: 12, op: 'mock-op-12' },
-            { v: 13, op: 'mock-op-13' }
+            { v: 13, op: 'mock-op-13' },
           ]
           this.MongoManager.peekLastCompressedUpdate = sinon
             .stub()
@@ -250,7 +250,7 @@ describe('UpdatesManager', function () {
             { v: 10, op: 'mock-op-10' },
             { v: 11, op: 'mock-op-11' },
             { v: 12, op: 'mock-op-12' },
-            { v: 13, op: 'mock-op-13' }
+            { v: 13, op: 'mock-op-13' },
           ]
 
           return this.UpdatesManager.compressAndSaveRawUpdates(
@@ -303,7 +303,7 @@ describe('UpdatesManager', function () {
         beforeEach(function () {
           this.rawUpdates = [
             { v: 13, op: 'mock-op-13' },
-            { v: 12, op: 'mock-op-12' }
+            { v: 12, op: 'mock-op-12' },
           ]
           return this.UpdatesManager.compressAndSaveRawUpdates(
             this.project_id,
@@ -347,7 +347,7 @@ describe('UpdatesManager', function () {
         beforeEach(function () {
           this.rawUpdates = [
             { v: 12, op: 'mock-op-12' },
-            { v: 13, op: 'mock-op-13' }
+            { v: 13, op: 'mock-op-13' },
           ]
           return this.UpdatesManager.compressAndSaveRawUpdates(
             this.project_id,
@@ -454,7 +454,7 @@ describe('UpdatesManager', function () {
           'mock-update-1',
           'mock-update-2',
           'mock-update-3',
-          'mock-update-4'
+          'mock-update-4',
         ]
         this.redisArray = this.updates.slice()
         this.RedisManager.getOldestDocUpdates = (
@@ -673,7 +673,7 @@ describe('UpdatesManager', function () {
     })
 
     it('should process the doc ops for the each doc_id', function () {
-      return Array.from(this.doc_ids).map((doc_id) =>
+      return Array.from(this.doc_ids).map(doc_id =>
         this.UpdatesManager._processUncompressedUpdatesForDocWithLock
           .calledWith(this.project_id, doc_id, this.temporary)
           .should.equal(true)
@@ -692,26 +692,26 @@ describe('UpdatesManager', function () {
           doc_id: 123,
           v: 456,
           op: 'mock-updates',
-          meta: { user_id: 123, start_ts: 1233, end_ts: 1234 }
-        }
+          meta: { user_id: 123, start_ts: 1233, end_ts: 1234 },
+        },
       ]
       this.options = { before: 'mock-before', limit: 'mock-limit' }
       this.summarizedUpdates = [
         {
           meta: { user_ids: [123], start_ts: 1233, end_ts: 1234 },
-          docs: { '123': { fromV: 456, toV: 456 } }
-        }
+          docs: { 123: { fromV: 456, toV: 456 } },
+        },
       ]
       this.updatesWithUserInfo = ['updates-with-user-info']
       this.done_state = false
       this.iterator = {
-        next: (cb) => {
+        next: cb => {
           this.done_state = true
           return cb(null, this.updates)
         },
         done: () => {
           return this.done_state
-        }
+        },
       }
       this.PackManager.makeProjectIterator = sinon
         .stub()
@@ -867,22 +867,22 @@ describe('UpdatesManager', function () {
         this.updates = [
           {
             meta: {
-              user_id: this.user_id_1
+              user_id: this.user_id_1,
             },
-            op: 'mock-op-1'
+            op: 'mock-op-1',
           },
           {
             meta: {
-              user_id: this.user_id_1
+              user_id: this.user_id_1,
             },
-            op: 'mock-op-2'
+            op: 'mock-op-2',
           },
           {
             meta: {
-              user_id: this.user_id_2
+              user_id: this.user_id_2,
             },
-            op: 'mock-op-3'
-          }
+            op: 'mock-op-3',
+          },
         ]
         this.user_info = {}
         this.user_info[this.user_id_1] = { email: 'user1@sharelatex.com' }
@@ -920,27 +920,27 @@ describe('UpdatesManager', function () {
           {
             meta: {
               user: {
-                email: 'user1@sharelatex.com'
-              }
+                email: 'user1@sharelatex.com',
+              },
             },
-            op: 'mock-op-1'
+            op: 'mock-op-1',
           },
           {
             meta: {
               user: {
-                email: 'user1@sharelatex.com'
-              }
+                email: 'user1@sharelatex.com',
+              },
             },
-            op: 'mock-op-2'
+            op: 'mock-op-2',
           },
           {
             meta: {
               user: {
-                email: 'user2@sharelatex.com'
-              }
+                email: 'user2@sharelatex.com',
+              },
             },
-            op: 'mock-op-3'
-          }
+            op: 'mock-op-3',
+          },
         ])
       })
     })
@@ -950,16 +950,16 @@ describe('UpdatesManager', function () {
         this.updates = [
           {
             meta: {
-              user_id: null
+              user_id: null,
             },
-            op: 'mock-op-1'
+            op: 'mock-op-1',
           },
           {
             meta: {
-              user_id: 'anonymous-user'
+              user_id: 'anonymous-user',
             },
-            op: 'mock-op-2'
-          }
+            op: 'mock-op-2',
+          },
         ]
         this.WebApiManager.getUserInfo = (user_id, callback) => {
           if (callback == null) {
@@ -986,12 +986,12 @@ describe('UpdatesManager', function () {
         return expect(this.results).to.deep.equal([
           {
             meta: {},
-            op: 'mock-op-1'
+            op: 'mock-op-1',
           },
           {
             meta: {},
-            op: 'mock-op-2'
-          }
+            op: 'mock-op-2',
+          },
         ])
       })
     })
@@ -1011,19 +1011,19 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now + 20,
-            end_ts: this.now + 30
+            end_ts: this.now + 30,
           },
-          v: 5
+          v: 5,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: this.user_2.id,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
-        }
+          v: 4,
+        },
       ])
 
       return expect(result).to.deep.equal([
@@ -1031,15 +1031,15 @@ describe('UpdatesManager', function () {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [this.user_1.id, this.user_2.id],
             start_ts: this.now,
-            end_ts: this.now + 30
-          }
-        }
+            end_ts: this.now + 30,
+          },
+        },
       ])
     })
 
@@ -1051,47 +1051,47 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: this.user_2.id,
             start_ts: this.now + oneDay,
-            end_ts: this.now + oneDay + 10
+            end_ts: this.now + oneDay + 10,
           },
-          v: 5
+          v: 5,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
-        }
+          v: 4,
+        },
       ])
       return expect(result).to.deep.equal([
         {
           docs: {
             'doc-id-1': {
               fromV: 5,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [this.user_2.id],
             start_ts: this.now + oneDay,
-            end_ts: this.now + oneDay + 10
-          }
+            end_ts: this.now + oneDay + 10,
+          },
         },
         {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 4
-            }
+              toV: 4,
+            },
           },
           meta: {
             user_ids: [this.user_1.id],
             start_ts: this.now,
-            end_ts: this.now + 10
-          }
-        }
+            end_ts: this.now + 10,
+          },
+        },
       ])
     })
 
@@ -1103,34 +1103,34 @@ describe('UpdatesManager', function () {
             meta: {
               user_id: this.user_1.id,
               start_ts: this.now + 20,
-              end_ts: this.now + 30
+              end_ts: this.now + 30,
             },
-            v: 5
+            v: 5,
           },
           {
             doc_id: 'doc-id-2',
             meta: {
               user_id: this.user_2.id,
               start_ts: this.now,
-              end_ts: this.now + 10
+              end_ts: this.now + 10,
             },
-            v: 4
-          }
+            v: 4,
+          },
         ],
         [
           {
             docs: {
               'doc-id-1': {
                 fromV: 6,
-                toV: 8
-              }
+                toV: 8,
+              },
             },
             meta: {
               user_ids: [this.user_1.id],
               start_ts: this.now + 40,
-              end_ts: this.now + 50
-            }
-          }
+              end_ts: this.now + 50,
+            },
+          },
         ]
       )
       return expect(result).to.deep.equal([
@@ -1138,19 +1138,19 @@ describe('UpdatesManager', function () {
           docs: {
             'doc-id-1': {
               toV: 8,
-              fromV: 6
+              fromV: 6,
             },
             'doc-id-2': {
               toV: 5,
-              fromV: 4
-            }
+              fromV: 4,
+            },
           },
           meta: {
             user_ids: [this.user_1.id, this.user_2.id],
             start_ts: this.now,
-            end_ts: this.now + 50
-          }
-        }
+            end_ts: this.now + 50,
+          },
+        },
       ])
     })
 
@@ -1161,34 +1161,34 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now + 20,
-            end_ts: this.now + 30
+            end_ts: this.now + 30,
           },
-          v: 5
+          v: 5,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: null,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
-        }
+          v: 4,
+        },
       ])
       return expect(result).to.deep.equal([
         {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [this.user_1.id, null],
             start_ts: this.now,
-            end_ts: this.now + 30
-          }
-        }
+            end_ts: this.now + 30,
+          },
+        },
       ])
     })
 
@@ -1199,34 +1199,34 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: null,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
+          v: 4,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now + 20,
-            end_ts: this.now + 30
+            end_ts: this.now + 30,
           },
-          v: 5
-        }
+          v: 5,
+        },
       ])
       return expect(result).to.deep.equal([
         {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [null, this.user_1.id],
             start_ts: this.now,
-            end_ts: this.now + 30
-          }
-        }
+            end_ts: this.now + 30,
+          },
+        },
       ])
     })
 
@@ -1237,43 +1237,43 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now + 20,
-            end_ts: this.now + 30
+            end_ts: this.now + 30,
           },
-          v: 5
+          v: 5,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: null,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
+          v: 4,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: null,
             start_ts: this.now + 2,
-            end_ts: this.now + 4
+            end_ts: this.now + 4,
           },
-          v: 4
-        }
+          v: 4,
+        },
       ])
       return expect(result).to.deep.equal([
         {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [this.user_1.id, null],
             start_ts: this.now,
-            end_ts: this.now + 30
-          }
-        }
+            end_ts: this.now + 30,
+          },
+        },
       ])
     })
 
@@ -1285,19 +1285,19 @@ describe('UpdatesManager', function () {
           meta: {
             user_id: this.user_1.id,
             start_ts: this.now + 20,
-            end_ts: this.now + 30
+            end_ts: this.now + 30,
           },
-          v: 5
+          v: 5,
         },
         {
           doc_id: 'doc-id-1',
           meta: {
             user_id: this.user_2.id,
             start_ts: this.now,
-            end_ts: this.now + 10
+            end_ts: this.now + 10,
           },
-          v: 4
-        }
+          v: 4,
+        },
       ])
 
       return expect(result).to.deep.equal([
@@ -1305,28 +1305,28 @@ describe('UpdatesManager', function () {
           docs: {
             'doc-id-1': {
               fromV: 5,
-              toV: 5
-            }
+              toV: 5,
+            },
           },
           meta: {
             user_ids: [this.user_1.id],
             start_ts: this.now + 20,
-            end_ts: this.now + 30
-          }
+            end_ts: this.now + 30,
+          },
         },
         {
           docs: {
             'doc-id-1': {
               fromV: 4,
-              toV: 4
-            }
+              toV: 4,
+            },
           },
           meta: {
             user_ids: [this.user_2.id],
             start_ts: this.now,
-            end_ts: this.now + 10
-          }
-        }
+            end_ts: this.now + 10,
+          },
+        },
       ])
     })
   })
diff --git a/services/track-changes/test/unit/js/WebApiManager/WebApiManagerTests.js b/services/track-changes/test/unit/js/WebApiManager/WebApiManagerTests.js
index ce2f6f6890..9caba5185e 100644
--- a/services/track-changes/test/unit/js/WebApiManager/WebApiManagerTests.js
+++ b/services/track-changes/test/unit/js/WebApiManager/WebApiManagerTests.js
@@ -24,11 +24,11 @@ describe('WebApiManager', function () {
             web: {
               url: 'http://example.com',
               user: 'sharelatex',
-              pass: 'password'
-            }
-          }
-        })
-      }
+              pass: 'password',
+            },
+          },
+        }),
+      },
     })
     this.callback = sinon.stub()
     this.user_id = 'mock-user-id'
@@ -38,7 +38,7 @@ describe('WebApiManager', function () {
       id: this.user_id,
       first_name: 'Leo',
       last_nane: 'Lion',
-      extra_param: 'blah'
+      extra_param: 'blah',
     }
     return (this.project = { features: 'mock-features' })
   })
@@ -60,8 +60,8 @@ describe('WebApiManager', function () {
             auth: {
               user: this.settings.apis.web.user,
               pass: this.settings.apis.web.pass,
-              sendImmediately: true
-            }
+              sendImmediately: true,
+            },
           })
           .should.equal(true)
       })
@@ -72,7 +72,7 @@ describe('WebApiManager', function () {
             id: this.user_id,
             email: this.user_info.email,
             first_name: this.user_info.first_name,
-            last_name: this.user_info.last_name
+            last_name: this.user_info.last_name,
           })
           .should.equal(true)
       })
@@ -150,8 +150,8 @@ describe('WebApiManager', function () {
             auth: {
               user: this.settings.apis.web.user,
               pass: this.settings.apis.web.pass,
-              sendImmediately: true
-            }
+              sendImmediately: true,
+            },
           })
           .should.equal(true)
       })