diff --git a/services/clsi/app/js/OutputFileFinder.js b/services/clsi/app/js/OutputFileFinder.js
index f863e0c1ed..d9d2499699 100644
--- a/services/clsi/app/js/OutputFileFinder.js
+++ b/services/clsi/app/js/OutputFileFinder.js
@@ -1,66 +1,38 @@
-/* eslint-disable
-    handle-callback-err,
-    no-return-assign,
-    no-unused-vars,
-    no-useless-escape,
-*/
-// TODO: This file was created by bulk-decaffeinate.
-// Fix any style issues and re-enable lint.
-/*
- * decaffeinate suggestions:
- * DS101: Remove unnecessary use of Array.from
- * DS102: Remove unnecessary code created because of implicit returns
- * DS103: Rewrite code to no longer use __guard__
- * DS207: Consider shorter variations of null checks
- * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
- */
 let OutputFileFinder
-const async = require('async')
-const fs = require('fs')
 const Path = require('path')
+const _ = require('lodash')
 const { spawn } = require('child_process')
 const logger = require('logger-sharelatex')
 
 module.exports = OutputFileFinder = {
   findOutputFiles(resources, directory, callback) {
-    if (callback == null) {
-      callback = function (error, outputFiles, allFiles) {}
-    }
-    const incomingResources = {}
-    for (const resource of Array.from(resources)) {
-      incomingResources[resource.path] = true
-    }
+    const incomingResources = new Set(
+      resources.map((resource) => resource.path)
+    )
 
-    return OutputFileFinder._getAllFiles(directory, function (error, allFiles) {
+    OutputFileFinder._getAllFiles(directory, function (error, allFiles) {
       if (allFiles == null) {
         allFiles = []
       }
-      if (error != null) {
+      if (error) {
         logger.err({ err: error }, 'error finding all output files')
         return callback(error)
       }
       const outputFiles = []
-      for (const file of Array.from(allFiles)) {
-        if (!incomingResources[file]) {
+      for (const file of allFiles) {
+        if (!incomingResources.has(file)) {
           outputFiles.push({
             path: file,
-            type: __guard__(file.match(/\.([^\.]+)$/), (x) => x[1])
+            type: Path.extname(file).replace(/^\./, '') || undefined
           })
         }
       }
-      return callback(null, outputFiles, allFiles)
+      callback(null, outputFiles, allFiles)
     })
   },
 
-  _getAllFiles(directory, _callback) {
-    if (_callback == null) {
-      _callback = function (error, fileList) {}
-    }
-    const callback = function (error, fileList) {
-      _callback(error, fileList)
-      return (_callback = function () {})
-    }
-
+  _getAllFiles(directory, callback) {
+    callback = _.once(callback)
     // don't include clsi-specific files/directories in the output list
     const EXCLUDE_DIRS = [
       '-name',
@@ -75,7 +47,7 @@ module.exports = OutputFileFinder = {
     const args = [
       directory,
       '(',
-      ...Array.from(EXCLUDE_DIRS),
+      ...EXCLUDE_DIRS,
       ')',
       '-prune',
       '-o',
@@ -89,7 +61,7 @@ module.exports = OutputFileFinder = {
     let stdout = ''
     proc.stdout.setEncoding('utf8').on('data', (chunk) => (stdout += chunk))
     proc.on('error', callback)
-    return proc.on('close', function (code) {
+    proc.on('close', function (code) {
       if (code !== 0) {
         logger.warn(
           { directory, code },
@@ -100,16 +72,9 @@ module.exports = OutputFileFinder = {
       let fileList = stdout.trim().split('\n')
       fileList = fileList.map(function (file) {
         // Strip leading directory
-        let path
-        return (path = Path.relative(directory, file))
+        return Path.relative(directory, file)
       })
-      return callback(null, fileList)
+      callback(null, fileList)
     })
   }
 }
-
-function __guard__(value, transform) {
-  return typeof value !== 'undefined' && value !== null
-    ? transform(value)
-    : undefined
-}
diff --git a/services/clsi/test/unit/js/OutputFileFinderTests.js b/services/clsi/test/unit/js/OutputFileFinderTests.js
index 4afa25e83e..8744c6e779 100644
--- a/services/clsi/test/unit/js/OutputFileFinderTests.js
+++ b/services/clsi/test/unit/js/OutputFileFinderTests.js
@@ -28,6 +28,9 @@ describe('OutputFileFinder', function () {
         fs: (this.fs = {}),
         child_process: { spawn: (this.spawn = sinon.stub()) },
         'logger-sharelatex': { log: sinon.stub(), warn: sinon.stub() }
+      },
+      globals: {
+        Math // used by lodash
       }
     })
     this.directory = '/test/dir'