return projectHistoryId in DocumentController.getDoc

services/web/app/coffee/Features/Documents/DocumentController.coffee

@@ -1,3 +1,4 @@
+ProjectGetter = require "../Project/ProjectGetter"
 ProjectLocator = require "../Project/ProjectLocator"
 ProjectEntityHandler = require "../Project/ProjectEntityHandler"
 ProjectEntityUpdateHandler = require "../Project/ProjectEntityUpdateHandler"
@@ -9,25 +10,31 @@ module.exports =
 		doc_id = req.params.doc_id
 		plain = req?.query?.plain == 'true'
 		logger.log doc_id:doc_id, project_id:project_id, "receiving get document request from api (docupdater)"
-		ProjectLocator.findElement {project_id: project_id, element_id: doc_id, type: 'doc'}, (error, doc, path) =>
-			if error?
-				logger.err err:error, doc_id:doc_id, project_id:project_id, "error finding element for getDocument"
-				return next(error)
-			ProjectEntityHandler.getDoc project_id, doc_id, (error, lines, rev, version, ranges) ->
+		ProjectGetter.getProject project_id, rootFolder: true, overleaf: true, (error, project) ->
+			return next(error) if error?
+			return res.sendStatus(404) if !project?
+			ProjectLocator.findElement {project: project, element_id: doc_id, type: 'doc'}, (error, doc, path) ->
 				if error?
-					logger.err err:error, doc_id:doc_id, project_id:project_id, "error finding doc contents for getDocument"
+					logger.err err:error, doc_id:doc_id, project_id:project_id, "error finding element for getDocument"
 					return next(error)
-				if plain
-					res.type "text/plain"
-					res.send lines.join('\n')
-				else
-					res.type "json"
-					res.send JSON.stringify {
-						lines: lines
-						version: version
-						ranges: ranges
-						pathname: path.fileSystem
-					}
+				ProjectEntityHandler.getDoc project_id, doc_id, (error, lines, rev, version, ranges) ->
+					if error?
+						logger.err err:error, doc_id:doc_id, project_id:project_id, "error finding doc contents for getDocument"
+						return next(error)
+					if plain
+						res.type "text/plain"
+						res.send lines.join('\n')
+
+					else
+						projectHistoryId = project?.overleaf?.history?.id
+						res.type "json"
+						res.send JSON.stringify {
+							lines: lines
+							version: version
+							ranges: ranges
+							pathname: path.fileSystem
+							projectHistoryId: projectHistoryId
+						}
 
 	setDocument: (req, res, next = (error) ->) ->
 		project_id = req.params.Project_id

services/web/test/unit/coffee/Documents/DocumentControllerTests.coffee

@@ -15,6 +15,7 @@ describe "DocumentController", ->
 			"logger-sharelatex":
 				log:->
 				err:->
+			"../Project/ProjectGetter": @ProjectGetter = {}
 			"../Project/ProjectLocator": @ProjectLocator = {}
 			"../Project/ProjectEntityHandler": @ProjectEntityHandler = {}
 			"../Project/ProjectEntityUpdateHandler": @ProjectEntityUpdateHandler = {}
@@ -35,39 +36,76 @@ describe "DocumentController", ->
 				Project_id: @project_id
 				doc_id: @doc_id
 
-		describe "when the document exists", ->
+		describe "when the project exists without project history enabled", ->
+			beforeEach ->
+				@project = _id: @project_id
+				@ProjectGetter.getProject = sinon.stub().callsArgWith(2, null, @project)
+
+			describe "when the document exists", ->
+				beforeEach ->
+					@doc = _id: @doc_id
+					@ProjectLocator.findElement = sinon.stub().callsArgWith(1, null, @doc, fileSystem: @pathname)
+					@ProjectEntityHandler.getDoc = sinon.stub().callsArgWith(2, null, @doc_lines, @rev, @version, @ranges)
+					@DocumentController.getDocument(@req, @res, @next)
+
+				it "should get the project", ->
+					@ProjectGetter.getProject
+						.calledWith(@project_id, rootFolder: true, overleaf: true)
+						.should.equal true
+
+				it "should get the pathname of the document", ->
+					@ProjectLocator.findElement
+						.calledWith({project: @project, element_id: @doc_id, type: 'doc'})
+						.should.equal true
+
+				it "should get the document content", ->
+					@ProjectEntityHandler.getDoc
+						.calledWith(@project_id, @doc_id)
+						.should.equal true
+
+				it "should return the document data to the client as JSON", ->
+					@res.type.should.equal "json"
+					@res.body.should.equal JSON.stringify
+						lines: @doc_lines
+						version: @version
+						ranges: @ranges
+						pathname: @pathname
+
+			describe "when the document doesn't exist", ->
+				beforeEach ->
+					@ProjectLocator.findElement = sinon.stub().callsArgWith(1, new Errors.NotFoundError("not found"))
+					@DocumentController.getDocument(@req, @res, @next)
+
+				it "should call next with the NotFoundError", ->
+					@next.calledWith(new Errors.NotFoundError("not found"))
+						.should.equal true
+
+		describe "when project exists with project history enabled", ->
 			beforeEach ->
 				@doc = _id: @doc_id
+				@projectHistoryId = 1234
+				@project = _id: @project_id, overleaf: history: id: @projectHistoryId
+				@ProjectGetter.getProject = sinon.stub().callsArgWith(2, null, @project)
 				@ProjectLocator.findElement = sinon.stub().callsArgWith(1, null, @doc, fileSystem: @pathname)
 				@ProjectEntityHandler.getDoc = sinon.stub().callsArgWith(2, null, @doc_lines, @rev, @version, @ranges)
 				@DocumentController.getDocument(@req, @res, @next)
 
-			it "should get the pathname of the document", ->
-				@ProjectLocator.findElement
-					.calledWith({project_id: @project_id, element_id: @doc_id, type: 'doc'})
-					.should.equal true
-
-			it "should get the document content", ->
-				@ProjectEntityHandler.getDoc
-					.calledWith(@project_id, @doc_id)
-					.should.equal true
-
-			it "should return the document data to the client as JSON", ->
+			it "should return the history id to the client as JSON", ->
 				@res.type.should.equal "json"
 				@res.body.should.equal JSON.stringify
 					lines: @doc_lines
 					version: @version
 					ranges: @ranges
 					pathname: @pathname
+					projectHistoryId: @projectHistoryId
 
-		describe "when the document doesn't exist", ->
+		describe "when the project does not exist", ->
 			beforeEach ->
-				@ProjectLocator.findElement = sinon.stub().callsArgWith(1, new Errors.NotFoundError("not found"))
+				@ProjectGetter.getProject = sinon.stub().callsArgWith(2, null, null)
 				@DocumentController.getDocument(@req, @res, @next)
 
-			it "should call next with the NotFoundError", ->
-				@next.calledWith(new Errors.NotFoundError("not found"))
-					.should.equal true
+			it "returns a 404", ->
+				@res.statusCode.should.equal 404
 
 	describe "setDocument", ->
 		beforeEach ->