Disable comment form when discussion locked for user

app/assets/javascripts/notes/components/issue_comment_form.vue

@@ -9,6 +9,7 @@
   import eventHub from '../event_hub';
   import issueWarning from '../../vue_shared/components/issue/issue_warning.vue';
   import issueNoteSignedOutWidget from './issue_note_signed_out_widget.vue';
+  import issueDiscussionLockedWidget from './issue_discussion_locked_widget.vue';
   import markdownField from '../../vue_shared/components/markdown/field.vue';
   import userAvatarLink from '../../vue_shared/components/user_avatar/user_avatar_link.vue';
   import issuableStateMixin from '../mixins/issuable_state';
@@ -29,6 +30,7 @@
     components: {
       issueWarning,
       issueNoteSignedOutWidget,
+      issueDiscussionLockedWidget,
       markdownField,
       userAvatarLink,
     },
@@ -239,6 +241,7 @@
 <template>
   <div>
     <issue-note-signed-out-widget v-if="!isLoggedIn" />
+    <issue-discussion-locked-widget v-else-if="!canCreate" />
     <ul
       v-else
       class="notes notes-form timeline">

app/assets/javascripts/notes/components/issue_discussion_locked_widget.vue

+<script>
+  import { mapGetters } from 'vuex';
+
+  export default {
+    name: 'discussionLockedWidget',
+  };
+
+</script>
+
+<template>
+  <div class="disabled-comment text-center">
+    <span class="issuable-note-warning">
+      This issue is locked. Only <b>project members</b> can comment.
+     </span>
+  </div>
+</template>

app/serializers/issue_entity.rb

@@ -15,7 +15,7 @@ class IssueEntity < IssuableEntity
 
   expose :current_user do
     expose :can_create_note do |issue|
-      can?(request.current_user, :create_note, issue.project)
+      can?(request.current_user, :create_note, issue)
     end
 
     expose :can_update do |issue|

app/views/shared/notes/_notes_with_form.html.haml

@@ -25,9 +25,11 @@
     = link_to "sign in", new_session_path(:user, redirect_to_referer: 'yes'), class: 'js-sign-in-link'
     to comment
 - elsif discussion_locked
-  .discussion_locked
-    %span
+  .disabled-comment.text-center.prepend-top-default
+    %span.issuable-note-warning
       This
-      = issuable.class.to_s
-      has been locked. Posting comments has been restricted to project members.
+      = issuable.class.to_s.titleize
+      is locked. Only
+      %b project members
+      can comment.
 %script.js-notes-data{ type: "application/json" }= initial_notes_data(autocomplete).to_json.html_safe