Disable autocomplete for epics

app/assets/javascripts/issue_show/components/app.vue

@@ -34,6 +34,11 @@ export default {
       required: false,
       default: true,
     },
+    enableAutocomplete: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
     issuableRef: {
       type: String,
       required: true,
@@ -240,6 +245,7 @@ export default {
       :project-namespace="projectNamespace"
       :show-delete-button="showDeleteButton"
       :can-attach-file="canAttachFile"
+      :enable-autocomplete="enableAutocomplete"
     />
     <div v-else>
       <title-component

app/assets/javascripts/issue_show/components/fields/description.vue

@@ -22,6 +22,11 @@
         required: false,
         default: true,
       },
+      enableAutocomplete: {
+        type: Boolean,
+        required: false,
+        default: true,
+      },
     },
     components: {
       markdownField,
@@ -42,7 +47,9 @@
     <markdown-field
       :markdown-preview-path="markdownPreviewPath"
       :markdown-docs-path="markdownDocsPath"
-      :can-attach-file="canAttachFile">
+      :can-attach-file="canAttachFile"
+      :enable-autocomplete="enableAutocomplete"
+    >
       <textarea
         id="issue-description"
         class="note-textarea js-gfm-input js-autosize markdown-area"

app/assets/javascripts/issue_show/components/form.vue

@@ -46,6 +46,11 @@
         required: false,
         default: true,
       },
+      enableAutocomplete: {
+        type: Boolean,
+        required: false,
+        default: true,
+      },
     },
     components: {
       lockedWarning,
@@ -89,7 +94,9 @@
       :form-state="formState"
       :markdown-preview-path="markdownPreviewPath"
       :markdown-docs-path="markdownDocsPath"
-      :can-attach-file="canAttachFile" />
+      :can-attach-file="canAttachFile"
+      :enable-autocomplete="enableAutocomplete"
+    />
     <edit-actions
       :form-state="formState"
       :can-destroy="canDestroy"

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

@@ -30,6 +30,11 @@
         required: false,
         default: true,
       },
+      enableAutocomplete: {
+        type: Boolean,
+        required: false,
+        default: true,
+      },
     },
     data() {
       return {
@@ -97,7 +102,7 @@
       /*
         GLForm class handles all the toolbar buttons
       */
-      return new GLForm($(this.$refs['gl-form']), true);
+      return new GLForm($(this.$refs['gl-form']), this.enableAutocomplete);
     },
     beforeDestroy() {
       const glForm = $(this.$refs['gl-form']).data('gl-form');

changelogs/unreleased-ee/disable-autocomplete.yml

+---
+title: Disable autocomplete for epics
+merge_request:
+author:
+type: fixed

ee/app/assets/javascripts/epics/epic_show/components/epic_show_app.vue

@@ -123,6 +123,7 @@
           :show-inline-edit-button="true"
           :show-delete-button="false"
           :can-attach-file="false"
+          :enable-autocomplete="false"
         />
       </div>
       <epic-sidebar

spec/ee/spec/features/epics/update_epic_spec.rb

@@ -50,6 +50,16 @@ feature 'Update Epic', :js do
 
       expect(page).not_to have_selector('.uploading-container .button-attach-file')
     end
+
+    # Autocomplete is disabled for epics until #4084 is resolved
+    describe 'autocomplete disabled' do
+      it 'does not open atwho container' do
+        find('.btn-edit').click
+
+        find('#issue-description').native.send_keys('@')
+        expect(page).not_to have_selector('.atwho-container')
+      end
+    end
   end
 
   context 'when user with owner access displays the epic' do