add changeEmail function to newsletter manager

not actually called

services/web/app/coffee/Features/Newsletter/NewsletterManager.coffee

@@ -4,14 +4,19 @@ Settings = require 'settings-sharelatex'
 crypto = require('crypto')
 Mailchimp = require('mailchimp-api-v3')
 
+
+if !Settings.mailchimp?.api_key?
+	logger.warn "No newsletter provider configured so not chaning email on user"
+	mailchimp =
+		request: (opts, cb)-> cb()
+else
+	mailchimp = new Mailchimp(Settings.mailchimp?.api_key)
+
 module.exports =
+
 	subscribe: (user, callback = () ->)->
-		if !Settings.mailchimp?
-			logger.warn "No newsletter provider configured so not subscribing user"
-			return callback()
 		options = buildOptions(user, true)
 		logger.log options:options, user:user, email:user.email, "trying to subscribe user to the mailing list"
-		mailchimp = new Mailchimp(Settings.mailchimp?.api_key)
 		mailchimp.request options, (err)->
 			if err?
 				logger.err err:err, "error subscribing person to newsletter"
@@ -20,12 +25,8 @@ module.exports =
 			callback(err)
 
 	unsubscribe: (user, callback = () ->)->
-		if !Settings.mailchimp?
-			logger.warn "No newsletter provider configured so not unsubscribing user"
-			return callback()
 		logger.log user:user, email:user.email, "trying to unsubscribe user to the mailing list"
 		options = buildOptions(user, false)
-		mailchimp = new Mailchimp(Settings.mailchimp?.api_key)
 		mailchimp.request options, (err)->
 			if err?
 				logger.err err:err, "error unsubscribing person to newsletter"
@@ -33,6 +34,19 @@ module.exports =
 				logger.log user:user, "finished unsubscribing user to the newsletter"
 			callback(err)
 
+	changeEmail: (oldEmail, newEmail, callback = ()->)->
+		options = buildOptions({email:oldEmail})
+		delete options.body.status
+		options.body.email_address = newEmail
+		mailchimp.request options, (err)->
+			# if the user has unsubscribed mailchimp will error on email address change
+			if err? and err?.message.indexOf("could not be validated") == -1
+				logger.err err:err, "error changing email in newsletter"
+				return callback(err)
+			else
+				logger.log "finished changing email in the newsletter"
+				return callback()
+
 hashEmail = (email)->
 	crypto.createHash('md5').update(email.toLowerCase()).digest("hex")
 

services/web/app/coffee/Features/User/UserUpdater.coffee

@@ -11,6 +11,7 @@ EmailHelper = require "../Helpers/EmailHelper"
 Errors = require "../Errors/Errors"
 Settings = require "settings-sharelatex"
 request = require 'request'
+NewsletterManager = require "../Newsletter/NewsletterManager"
 
 module.exports = UserUpdater =
 	updateUser: (query, update, callback = (error) ->) ->