Refactor LimitationsManager to use CollaboratorsHandler

services/web/app/coffee/Features/Subscription/LimitationsManager.coffee

@@ -3,6 +3,7 @@ Project = require("../../models/Project").Project
 User = require("../../models/User").User
 SubscriptionLocator = require("./SubscriptionLocator")
 Settings = require("settings-sharelatex")
+CollaboratorsHandler = require("../Collaborators/CollaboratorsHandler")
 
 module.exports =
 
@@ -13,16 +14,11 @@ module.exports =
 				callback null, owner.features.collaborators
 			else
 				callback null, Settings.defaultPlanCode.collaborators
-	
-	currentNumberOfCollaboratorsInProject: (project_id, callback) ->
-		Project.findById project_id, 'collaberator_refs readOnly_refs', (error, project) ->
-			return callback(error) if error?
-			callback null, (project.collaberator_refs.length + project.readOnly_refs.length)
 
 	canAddXCollaborators: (project_id, x_collaborators, callback = (error, allowed)->) ->
 		@allowedNumberOfCollaboratorsInProject project_id, (error, allowed_number) =>
 			return callback(error) if error?
-			@currentNumberOfCollaboratorsInProject project_id, (error, current_number) =>
+			CollaboratorsHandler.getCollaboratorCount project_id, (error, current_number) =>
 				return callback(error) if error?
 				if current_number + x_collaborators <= allowed_number or allowed_number < 0
 					callback null, true

services/web/test/UnitTests/coffee/Subscription/LimitationsManagerTests.coffee

@@ -29,6 +29,7 @@ describe "LimitationsManager", ->
 			'../../models/User' : User: @User
 			'./SubscriptionLocator':@SubscriptionLocator
 			'settings-sharelatex' : @Settings = {}
+			"../Collaborators/CollaboratorsHandler": @CollaboratorsHandler = {}
 			'logger-sharelatex':log:->
 
 	describe "allowedNumberOfCollaboratorsInProject", ->
@@ -51,22 +52,10 @@ describe "LimitationsManager", ->
 
 			it "should return the number of collaborators the user is allowed", ->
 				@callback.calledWith(null, @user.features.collaborators).should.equal true
-	
-	describe "currentNumberOfCollaboratorsInProject", ->
-		beforeEach ->
-			@project.collaberator_refs = ["one", "two"]
-			@project.readOnly_refs = ["three"]
-			@callback = sinon.stub()
-			@LimitationsManager.currentNumberOfCollaboratorsInProject(@project_id, @callback)
-
-		it "should return the total number of collaborators", ->
-			@callback.calledWith(null, 3).should.equal true
 
 	describe "canAddXCollaborators", ->
 		beforeEach ->
-			sinon.stub @LimitationsManager,
-					   "currentNumberOfCollaboratorsInProject",
-					   (project_id, callback) => callback(null, @current_number)
+			@CollaboratorsHandler.getCollaboratorCount = (project_id, callback) => callback(null, @current_number)
 			sinon.stub @LimitationsManager,
 					   "allowedNumberOfCollaboratorsInProject",
 					   (project_id, callback) => callback(null, @allowed_number)