Add `&` support for epics autocompletion

app/assets/javascripts/gfm_auto_complete.js

@@ -12,7 +12,7 @@ export const defaultAutocompleteConfig = {
   members: true,
   issues: true,
   mergeRequests: true,
-  epics: false,
+  epics: true,
   milestones: true,
   labels: true,
 };
@@ -493,6 +493,7 @@ GfmAutoComplete.atTypeMap = {
   '@': 'members',
   '#': 'issues',
   '!': 'mergeRequests',
+  '&': 'epics',
   '~': 'labels',
   '%': 'milestones',
   '/': 'commands',

app/assets/javascripts/gl_form.js

@@ -9,6 +9,13 @@ export default class GLForm {
     this.form = form;
     this.textarea = this.form.find('textarea.js-gfm-input');
     this.enableGFM = Object.assign({}, GFMConfig.defaultAutocompleteConfig, enableGFM);
+    // Disable autocomplete for keywords which do not have dataSources available
+    const dataSources = (gl.GfmAutoComplete && gl.GfmAutoComplete.dataSources) || {};
+    Object.keys(this.enableGFM).forEach(item => {
+      if (item !== 'emojis') {
+        this.enableGFM[item] = !!dataSources[item];
+      }
+    });
     // Before we start, we should clean up any previous data for this form
     this.destroy();
     // Setup the form

app/assets/javascripts/pages/snippets/form.js

@@ -8,6 +8,7 @@ export default () => {
     members: false,
     issues: false,
     mergeRequests: false,
+    epics: false,
     milestones: false,
     labels: false,
   });

app/assets/javascripts/shared/milestones/form.js

@@ -8,10 +8,11 @@ export default (initGFM = true) => {
   new DueDateSelectors(); // eslint-disable-line no-new
   // eslint-disable-next-line no-new
   new GLForm($('.milestone-form'), {
-    emojis: initGFM,
+    emojis: true,
     members: initGFM,
     issues: initGFM,
     mergeRequests: initGFM,
+    epics: initGFM,
     milestones: initGFM,
     labels: initGFM,
   });

app/assets/javascripts/vue_shared/components/markdown/field.vue

@@ -67,6 +67,7 @@
         members: this.enableAutocomplete,
         issues: this.enableAutocomplete,
         mergeRequests: this.enableAutocomplete,
+        epics: this.enableAutocomplete,
         milestones: this.enableAutocomplete,
         labels: this.enableAutocomplete,
       });

app/helpers/notes_helper.rb

@@ -148,6 +148,7 @@ module NotesHelper
         members: autocomplete,
         issues: autocomplete,
         mergeRequests: autocomplete,
+        epics: autocomplete,
         milestones: autocomplete,
         labels: autocomplete
       }