Merge pull request #27 from sharelatex/ja-verify-ranges

Add in a consistency check after applying updates that ranges still match

services/document-updater/app/coffee/RangesManager.coffee

@@ -5,7 +5,7 @@ module.exports = RangesManager =
 	MAX_COMMENTS: 500
 	MAX_CHANGES: 2000
 
-	applyUpdate: (project_id, doc_id, entries = {}, updates = [], callback = (error, new_entries) ->) ->
+	applyUpdate: (project_id, doc_id, entries = {}, updates = [], newDocLines, callback = (error, new_entries) ->) ->
 		{changes, comments} = entries
 		rangesTracker = new RangesTracker(changes, comments)
 		for update in updates
@@ -21,6 +21,14 @@ module.exports = RangesManager =
 		if rangesTracker.changes?.length > RangesManager.MAX_CHANGES or rangesTracker.comments?.length > RangesManager.MAX_COMMENTS
 			return callback new Error("too many comments or tracked changes")
 
+		try
+			# This is a consistency check that all of our ranges and
+			# comments still match the corresponding text
+			rangesTracker.validate(newDocLines.join("\n"))
+		catch error
+			logger.error {err: error, project_id, doc_id, newDocLines, updates}, "error validating ranges"
+			return callback(error)
+
 		response = RangesManager._getRanges rangesTracker
 		logger.log {project_id, doc_id, changesCount: response.changes?.length, commentsCount: response.comments?.length}, "applied updates to ranges"
 		callback null, response

services/document-updater/app/coffee/RangesTracker.coffee

@@ -1,3 +1,6 @@
+# This file is shared between document-updater and web, so that the server and client share
+# an identical track changes implementation. Do not edit it directly in web or document-updater,
+# instead edit it at https://github.com/sharelatex/ranges-tracker, where it has a suite of tests
 load = () ->
 	class RangesTracker
 		# The purpose of this class is to track a set of inserts and deletes to a document, like
@@ -91,6 +94,18 @@ load = () ->
 			return if !change?
 			@_removeChange(change)
 		
+		validate: (text) ->
+			for change in @changes
+				if change.op.i?
+					content = text.slice(change.op.p, change.op.p + change.op.i.length)
+					if content != change.op.i
+						throw new Error("Change (#{JSON.stringify(change)}) doesn't match text (#{JSON.stringify(content)})")
+			for comment in @comments
+				content = text.slice(comment.op.p, comment.op.p + comment.op.c.length)
+				if content != comment.op.c
+					throw new Error("Comment (#{JSON.stringify(comment)}) doesn't match text (#{JSON.stringify(content)})")
+			return true
+
 		applyOp: (op, metadata = {}) ->
 			metadata.ts ?= new Date()
 			# Apply an op that has been applied to the document to our changes to keep them up to date

services/document-updater/app/coffee/UpdateManager.coffee

@@ -59,7 +59,7 @@ module.exports = UpdateManager =
 				return callback(new Errors.NotFoundError("document not found: #{doc_id}"))
 			ShareJsUpdateManager.applyUpdate project_id, doc_id, update, lines, version, (error, updatedDocLines, version, appliedOps) ->
 				return callback(error) if error?
-				RangesManager.applyUpdate project_id, doc_id, ranges, appliedOps, (error, new_ranges) ->
+				RangesManager.applyUpdate project_id, doc_id, ranges, appliedOps, updatedDocLines, (error, new_ranges) ->
 					return callback(error) if error?
 					RedisManager.updateDocument doc_id, updatedDocLines, version, appliedOps, new_ranges, (error) ->
 						return callback(error) if error?

services/document-updater/test/unit/coffee/RangesManager/RangesManagerTests.coffee

@@ -0,0 +1,179 @@
+sinon = require('sinon')
+chai = require('chai')
+should = chai.should()
+expect = chai.expect
+modulePath = "../../../../app/js/RangesManager.js"
+SandboxedModule = require('sandboxed-module')
+
+describe "RangesManager", ->
+	beforeEach ->
+		@RangesManager = SandboxedModule.require modulePath,
+			requires:
+				"logger-sharelatex": @logger = { error: sinon.stub(), log: sinon.stub(), warn: sinon.stub() }
+		
+		@doc_id = "doc-id-123"
+		@project_id = "project-id-123"
+		@user_id = "user-id-123"
+		@callback = sinon.stub()
+
+	describe "applyUpdate", ->
+		beforeEach ->
+			@updates = [{
+				meta:
+					user_id: @user_id
+				op: [{
+					i: "two "
+					p: 4
+				}]
+			}]
+			@entries = {
+				comments: [{
+					op:
+						c: "three "
+						p: 4
+					metadata:
+						user_id: @user_id
+				}]
+				changes: [{
+					op:
+						i: "five"
+						p: 15
+					metadata:
+						user_id: @user_id
+				}]
+			}
+			@newDocLines = ["one two three four five"] # old is "one three four five"
+		
+		describe "successfully", ->
+			beforeEach ->
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return the modified the comments and changes", ->
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.be.null
+				entries.comments[0].op.should.deep.equal {
+					c: "three "
+					p: 8
+				}
+				entries.changes[0].op.should.deep.equal {
+					i: "five"
+					p: 19
+				}
+		
+		describe "with empty comments", ->
+			beforeEach ->
+				@entries.comments = []
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return an object with no comments", ->
+				# Save space in redis and don't store just {}
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.be.null
+				expect(entries.comments).to.be.undefined
+		
+		describe "with empty changes", ->
+			beforeEach ->
+				@entries.changes = []
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return an object with no changes", ->
+				# Save space in redis and don't store just {}
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.be.null
+				expect(entries.changes).to.be.undefined
+	
+		describe "with too many comments", ->
+			beforeEach ->
+				@RangesManager.MAX_COMMENTS = 2
+				@updates = [{
+					meta:
+						user_id: @user_id
+					op: [{
+						c: "one"
+						p: 0
+					}]
+				}]
+				@entries = {
+					comments: [{
+						op:
+							c: "three "
+							p: 4
+						metadata:
+							user_id: @user_id
+					}, {
+						op:
+							c: "four "
+							p: 10
+						metadata:
+							user_id: @user_id
+					}]
+					changes: []
+				}
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return an error", ->
+				# Save space in redis and don't store just {}
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.not.be.null
+				expect(error.message).to.equal("too many comments or tracked changes")
+		
+		describe "with too many changes", ->
+			beforeEach ->
+				@RangesManager.MAX_CHANGES = 2
+				@updates = [{
+					meta:
+						user_id: @user_id
+						tc: "track-changes-id-yes"
+					op: [{
+						i: "one "
+						p: 0
+					}]
+				}]
+				@entries = {
+					changes: [{
+						op:
+							i: "three"
+							p: 4
+						metadata:
+							user_id: @user_id
+					}, {
+						op:
+							i: "four"
+							p: 10
+						metadata:
+							user_id: @user_id
+					}]
+					comments: []
+				}
+				@newDocLines = ["one two three four"]
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return an error", ->
+				# Save space in redis and don't store just {}
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.not.be.null
+				expect(error.message).to.equal("too many comments or tracked changes")
+		
+		describe "inconsistent changes", ->
+			beforeEach ->
+				@updates = [{
+					meta:
+						user_id: @user_id
+					op: [{
+						c: "doesn't match"
+						p: 0
+					}]
+				}]
+				@RangesManager.applyUpdate @project_id, @doc_id, @entries, @updates, @newDocLines, @callback
+			
+			it "should return an error", ->
+				# Save space in redis and don't store just {}
+				@callback.called.should.equal true
+				[error, entries] = @callback.args[0]
+				expect(error).to.not.be.null
+				expect(error.message).to.equal("Change ({\"op\":{\"i\":\"five\",\"p\":15},\"metadata\":{\"user_id\":\"user-id-123\"}}) doesn't match text (\"our \")")

services/document-updater/test/unit/coffee/UpdateManager/UpdateManagerTests.coffee

@@ -179,7 +179,7 @@ describe "UpdateManager", ->
 			
 			it "should update the ranges", ->
 				@RangesManager.applyUpdate
-					.calledWith(@project_id, @doc_id, @ranges, @appliedOps)
+					.calledWith(@project_id, @doc_id, @ranges, @appliedOps, @updatedDocLines)
 					.should.equal true
 
 			it "should save the document", ->