Support for sending PMs to email addresses (#4988)

* Added support for sending PMs to email addresses.

* Made changes after review.

* Added settings validator.

* Fixed tests.

app/assets/javascripts/discourse/components/user-selector.js.es6

@@ -42,8 +42,11 @@ export default TextField.extend({
       updateData: (opts && opts.updateData) ? opts.updateData : false,
 
       dataSource: function(term) {
+        const termRegex = Discourse.User.currentProp('can_send_private_email_messages') ?
+          /[^a-zA-Z0-9_\-\.@\+]/ : /[^a-zA-Z0-9_\-\.]/;
+
         var results = userSearch({
-          term: term.replace(/[^a-zA-Z0-9_\-\.]/, ''),
+          term: term.replace(termRegex, ''),
           topicId: self.get('topicId'),
           exclude: excludedUsernames(),
           includeGroups,

app/assets/javascripts/discourse/lib/user-search.js.es6

@@ -46,6 +46,7 @@ function organizeResults(r, options) {
   var exclude = options.exclude || [],
       limit = options.limit || 5,
       users = [],
+      emails = [],
       groups = [],
       results = [];
 
@@ -59,6 +60,12 @@ function organizeResults(r, options) {
     });
   }
 
+  if (options.term.match(/@/)) {
+    let e = { username: options.term };
+    emails = [ e ];
+    results.push(e);
+  }
+
   if (r.groups) {
     r.groups.every(function(g) {
       if (results.length > limit && options.term.toLowerCase() !== g.name.toLowerCase()) return false;
@@ -71,6 +78,7 @@ function organizeResults(r, options) {
   }
 
   results.users = users;
+  results.emails = emails;
   results.groups = groups;
   return results;
 }
@@ -94,7 +102,7 @@ export default function userSearch(options) {
 
   return new Ember.RSVP.Promise(function(resolve) {
     // TODO site setting for allowed regex in username
-    if (term.match(/[^\w\.\-]/)) {
+    if (term.match(/[^\w_\-\.@\+]/)) {
       resolve([]);
       return;
     }

app/assets/javascripts/discourse/templates/user-selector-autocomplete.raw.hbs

@@ -9,6 +9,18 @@
         </a>
       </li>
     {{/each}}
+
+    {{#if options.emails}}
+      {{#each options.emails as |email|}}
+        <li>
+          <a href title="{{email.username}}">
+            <i class='fa fa-envelope'></i>
+            <span class='username'>{{email.username}}</span>
+          </a>
+        </li>
+      {{/each}}
+    {{/if}}
+
     {{#if options.groups}}
       {{#each options.groups as |group|}}
         <li>