added a change privlage level for user to new collab handler, won't work yet but is starting point

services/web/app/coffee/Features/Collaborators/CollaboratorsHandler.coffee

@@ -0,0 +1,17 @@
+User = require('../models/User').User
+Settings = require('settings-sharelatex')
+EmailHandler = require("../Email/EmailHandler")
+projectEntityHandler = require '../Project/ProjectEntityHandler'
+mimelib = require("mimelib")
+
+
+
+module.exports =
+
+
+
+	changeUsersPrivlageLevel: (project_id, user_id, newPrivalageLevel, callback)->
+		@removeUserFromProject project_id, user_id, =>
+		  User.findById user_id, (err, user)=>
+			  @addUserToProject project_id, user_id, newPrivalageLevel, callback
+

services/web/app/coffee/handlers/ProjectHandler.coffee

@@ -74,10 +74,4 @@ module.exports = class ProjectHandler
 			if err?
 				logger.err err: err, "problem removing user from project collaberators"
 			if callback?
-				callback()
-
-	changeUsersPrivlageLevel: (project_id, user_id, newPrivalageLevel)->
-		@removeUserFromProject project_id, user_id, ()=>
-		  User.findById user_id, (err, user)=>
-			if user
-			  @addUserToProject project_id, user.email, newPrivalageLevel
+				callback()

services/web/test/UnitTests/coffee/Collaborators/CollaboratorsHandlerTests.coffee

@@ -0,0 +1,39 @@
+should = require('chai').should()
+SandboxedModule = require('sandboxed-module')
+assert = require('assert')
+path = require('path')
+sinon = require('sinon')
+modulePath = path.join __dirname, "../../../../app/js/Features/Collaborators/CollaboratorsHandler"
+expect = require("chai").expect
+
+describe "CollaboratorsHandler", ->
+
+	beforeEach ->
+
+		@user =
+			email:"bob@bob.com"
+		@UserModel = 
+			findById:sinon.stub().callsArgWith(1, null, @user)
+
+		@settings = {}
+		@CollaboratorHandler = SandboxedModule.require modulePath, requires:
+			"settings-sharelatex":@settings
+			"logger-sharelatex": log:->
+			'../models/User': User:@UserModel
+
+		@project_id = "123l2j13lkj"
+		@user_id = "132kj1lk2j"
+
+	describe "changeUsersPrivlageLevel", ->
+
+
+		it "should call removeUserFromProject then addUserToProject", (done)->
+			@CollaboratorHandler.removeUserFromProject = sinon.stub().callsArgWith(2)
+			@CollaboratorHandler.addUserToProject = sinon.stub().callsArgWith(3)
+			newPrivalageLevel = "readAndWrite"
+			@CollaboratorHandler.changeUsersPrivlageLevel @project_id, @user_id, newPrivalageLevel, =>
+				@CollaboratorHandler.removeUserFromProject.calledWith(@project_id, @user_id).should.equal true
+				@CollaboratorHandler.addUserToProject.calledWith(@project_id, @user_id, newPrivalageLevel)
+				done()
+
+