Enable imports in custom email templates (#6052)

* Enable imports in custom email templates

* Compile emails on config change

* Add error logging

* Add emailer tests

* Fix tests

* Only build when config changes

src/controllers/admin/settings.js

@@ -1,12 +1,8 @@
 'use strict';
 
 var async = require('async');
-var nconf = require('nconf');
-var fs = require('fs');
-var path = require('path');
 
 var meta = require('../../meta');
-var file = require('../../file');
 var emailer = require('../../emailer');
 
 var settingsController = module.exports;
@@ -26,42 +22,8 @@ settingsController.get = function (req, res, next) {
 
 
 function renderEmail(req, res, next) {
-	var emailsPath = path.join(nconf.get('views_dir'), 'emails');
-
 	async.parallel({
-		emails: function (cb) {
-			async.waterfall([
-				function (next) {
-					file.walk(emailsPath, next);
-				},
-				function (emails, next) {
-					// exclude .js files
-					emails = emails.filter(function (email) {
-						return !email.endsWith('.js');
-					});
-
-					async.map(emails, function (email, next) {
-						var path = email.replace(emailsPath, '').substr(1).replace('.tpl', '');
-
-						async.waterfall([
-							function (next) {
-								fs.readFile(email, 'utf8', next);
-							},
-							function (original, next) {
-								var text = meta.config['email:custom:' + path] ? meta.config['email:custom:' + path] : original;
-
-								next(null, {
-									path: path,
-									fullpath: email,
-									text: text,
-									original: original,
-								});
-							},
-						], next);
-					}, next);
-				},
-			], cb);
-		},
+		emails: async.apply(emailer.getTemplates, meta.config),
 		services: emailer.listServices,
 	}, function (err, results) {
 		if (err) {