Add real-time note edits :chipmunk:

9 files changed, 320 insertions, 131 deletions

diff --git a/app/assets/javascripts/gl_form.js b/app/assets/javascripts/gl_form.js
index ff10f19a4fe..ff06092e4d6 100644
--- a/app/assets/javascripts/gl_form.js
+++ b/app/assets/javascripts/gl_form.js
@@ -34,9 +34,9 @@ GLForm.prototype.setupForm = function() {
     gl.GfmAutoComplete.setup(this.form.find('.js-gfm-input'));
     new DropzoneInput(this.form);
     autosize(this.textarea);
-    // form and textarea event listeners
-    this.addEventListeners();
   }
+  // form and textarea event listeners
+  this.addEventListeners();
   gl.text.init(this.form);
   // hide discard button
   this.form.find('.js-note-discard').hide();
diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index 974fb0d83da..87f03a40eba 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -4,6 +4,7 @@
 /* global ResolveService */
 /* global mrRefreshWidgetUrl */
 
+import $ from 'jquery';
 import Cookies from 'js-cookie';
 import CommentTypeToggle from './comment_type_toggle';
 
@@ -16,6 +17,10 @@ require('vendor/jquery.caret'); // required by jquery.atwho
 require('vendor/jquery.atwho');
 require('./task_list');
 
+const normalizeNewlines = function(str) {
+  return str.replace(/\r\n/g, '\n');
+};
+
 (function() {
   var bind = function(fn, me) { return function() { return fn.apply(me, arguments); }; };
 
@@ -42,13 +47,17 @@ require('./task_list');
       this.refresh = bind(this.refresh, this);
       this.keydownNoteText = bind(this.keydownNoteText, this);
       this.toggleCommitList = bind(this.toggleCommitList, this);
+
       this.notes_url = notes_url;
       this.note_ids = note_ids;
+      // Used to keep track of updated notes while people are editing things
+      this.updatedNotesTrackingMap = {};
       this.last_fetched_at = last_fetched_at;
       this.noteable_url = document.URL;
       this.notesCountBadge || (this.notesCountBadge = $(".issuable-details").find(".notes-tab .badge"));
       this.basePollingInterval = 15000;
       this.maxPollingSteps = 4;
+
       this.cleanBinding();
       this.addBinding();
       this.setPollingInterval();
@@ -128,7 +137,7 @@ require('./task_list');
       $(document).off("click", ".js-discussion-reply-button");
       $(document).off("click", ".js-add-diff-note-button");
       $(document).off("visibilitychange");
-      $(document).off("keyup", ".js-note-text");
+      $(document).off("keyup input", ".js-note-text");
       $(document).off("click", ".js-note-target-reopen");
       $(document).off("click", ".js-note-target-close");
       $(document).off("click", ".js-note-discard");
@@ -267,20 +276,20 @@ require('./task_list');
       return this.initRefresh();
     };
 
-    Notes.prototype.handleCreateChanges = function(note) {
+    Notes.prototype.handleCreateChanges = function(noteEntity) {
       var votesBlock;
-      if (typeof note === 'undefined') {
+      if (typeof noteEntity === 'undefined') {
         return;
       }
 
-      if (note.commands_changes) {
-        if ('merge' in note.commands_changes) {
+      if (noteEntity.commands_changes) {
+        if ('merge' in noteEntity.commands_changes) {
           $.get(mrRefreshWidgetUrl);
         }
 
-        if ('emoji_award' in note.commands_changes) {
+        if ('emoji_award' in noteEntity.commands_changes) {
           votesBlock = $('.js-awards-block').eq(0);
-          gl.awardsHandler.addAwardToEmojiBar(votesBlock, note.commands_changes.emoji_award);
+          gl.awardsHandler.addAwardToEmojiBar(votesBlock, noteEntity.commands_changes.emoji_award);
           return gl.awardsHandler.scrollToAwards();
         }
       }
@@ -292,41 +301,76 @@ require('./task_list');
     Note: for rendering inline notes use renderDiscussionNote
      */
 
-    Notes.prototype.renderNote = function(note, $form) {
-      var $notesList;
-      if (note.discussion_html != null) {
-        return this.renderDiscussionNote(note, $form);
+    Notes.prototype.renderNote = function(noteEntity, $form, $notesList = $('.main-notes-list')) {
+      if (noteEntity.discussion_html != null) {
+        return this.renderDiscussionNote(noteEntity, $form);
       }
 
-      if (!note.valid) {
-        if (note.errors.commands_only) {
-          new Flash(note.errors.commands_only, 'notice', this.parentTimeline);
+      if (!noteEntity.valid) {
+        if (noteEntity.errors.commands_only) {
+          new Flash(noteEntity.errors.commands_only, 'notice', this.parentTimeline);
           this.refresh();
         }
         return;
       }
 
-      if (this.isNewNote(note)) {
-        this.note_ids.push(note.id);
+      const $note = $notesList.find(`#note_${noteEntity.id}`);
+      if (this.isNewNote(noteEntity)) {
+        this.note_ids.push(noteEntity.id);
 
-        $notesList = window.$('ul.main-notes-list');
-        Notes.animateAppendNote(note.html, $notesList);
+        const $newNote = Notes.animateAppendNote(noteEntity.html, $notesList);
 
         // Update datetime format on the recent note
-        gl.utils.localTimeAgo($notesList.find("#note_" + note.id + " .js-timeago"), false);
+        gl.utils.localTimeAgo($newNote.find('.js-timeago'), false);
         this.collapseLongCommitList();
         this.taskList.init();
         this.refresh();
         return this.updateNotesCount(1);
       }
+      // The server can send the same update multiple times so we need to make sure to only update once per actual update.
+      else if (this.isUpdatedNote(noteEntity, $note)) {
+        const isEditing = $note.hasClass('is-editing');
+        const initialContent = normalizeNewlines(
+          $note.find('.original-note-content').text().trim()
+        );
+        const $textarea = $note.find('.js-note-text');
+        const currentContent = $textarea.val();
+        // There can be CRLF vs LF mismatches if we don't sanitize and compare the same way
+        const sanitizedNoteNote = normalizeNewlines(noteEntity.note);
+        const isTextareaUntouched = currentContent === initialContent || currentContent === sanitizedNoteNote;
+
+        if (isEditing && isTextareaUntouched) {
+          $textarea.val(noteEntity.note);
+          this.updatedNotesTrackingMap[noteEntity.id] = noteEntity;
+        }
+        else if (isEditing && !isTextareaUntouched) {
+          this.putConflictEditWarningInPlace(noteEntity, $note);
+          this.updatedNotesTrackingMap[noteEntity.id] = noteEntity;
+        }
+        else {
+          const $updatedNote = Notes.animateUpdateNote(noteEntity.html, $note);
+
+          // Update datetime format on the recent note
+          gl.utils.localTimeAgo($updatedNote.find('.js-timeago'), false);
+        }
+      }
     };
 
     /*
     Check if note does not exists on page
      */
 
-    Notes.prototype.isNewNote = function(note) {
-      return $.inArray(note.id, this.note_ids) === -1;
+    Notes.prototype.isNewNote = function(noteEntity) {
+      return $.inArray(noteEntity.id, this.note_ids) === -1;
+    };
+
+    Notes.prototype.isUpdatedNote = function(noteEntity, $note) {
+      // There can be CRLF vs LF mismatches if we don't sanitize and compare the same way
+      const sanitizedNoteNote = normalizeNewlines(noteEntity.note);
+      const currentNoteText = normalizeNewlines(
+        $note.find('.original-note-content').text().trim()
+      );
+      return sanitizedNoteNote !== currentNoteText;
     };
 
     Notes.prototype.isParallelView = function() {
@@ -339,31 +383,31 @@ require('./task_list');
     Note: for rendering inline notes use renderDiscussionNote
      */
 
-    Notes.prototype.renderDiscussionNote = function(note, $form) {
+    Notes.prototype.renderDiscussionNote = function(noteEntity, $form) {
       var discussionContainer, form, row, lineType, diffAvatarContainer;
-      if (!this.isNewNote(note)) {
+      if (!this.isNewNote(noteEntity)) {
         return;
       }
-      this.note_ids.push(note.id);
-      form = $form || $(".js-discussion-note-form[data-discussion-id='" + note.discussion_id + "']");
+      this.note_ids.push(noteEntity.id);
+      form = $form || $(".js-discussion-note-form[data-discussion-id='" + noteEntity.discussion_id + "']");
       row = form.closest("tr");
       lineType = this.isParallelView() ? form.find('#line_type').val() : 'old';
       diffAvatarContainer = row.prevAll('.line_holder').first().find('.js-avatar-container.' + lineType + '_line');
       // is this the first note of discussion?
-      discussionContainer = window.$(`.notes[data-discussion-id="${note.discussion_id}"]`);
+      discussionContainer = $(`.notes[data-discussion-id="${noteEntity.discussion_id}"]`);
       if (!discussionContainer.length) {
         discussionContainer = form.closest('.discussion').find('.notes');
       }
       if (discussionContainer.length === 0) {
-        if (note.diff_discussion_html) {
-          var $discussion = $(note.diff_discussion_html).renderGFM();
+        if (noteEntity.diff_discussion_html) {
+          var $discussion = $(noteEntity.diff_discussion_html).renderGFM();
 
           if (!this.isParallelView() || row.hasClass('js-temp-notes-holder')) {
             // insert the note and the reply button after the temp row
             row.after($discussion);
           } else {
             // Merge new discussion HTML in
-            var $notes = $discussion.find('.notes[data-discussion-id="' + note.discussion_id + '"]');
+            var $notes = $discussion.find('.notes[data-discussion-id="' + noteEntity.discussion_id + '"]');
             var contentContainerClass = '.' + $notes.closest('.notes_content')
               .attr('class')
               .split(' ')
@@ -373,17 +417,18 @@ require('./task_list');
           }
         }
         // Init discussion on 'Discussion' page if it is merge request page
-        if (window.$('body').attr('data-page').indexOf('projects:merge_request') === 0 || !note.diff_discussion_html) {
-          Notes.animateAppendNote(note.discussion_html, window.$('ul.main-notes-list'));
+        const page = $('body').attr('data-page');
+        if ((page && page.indexOf('projects:merge_request') === 0) || !noteEntity.diff_discussion_html) {
+          Notes.animateAppendNote(noteEntity.discussion_html, $('.main-notes-list'));
         }
       } else {
         // append new note to all matching discussions
-        Notes.animateAppendNote(note.html, discussionContainer);
+        Notes.animateAppendNote(noteEntity.html, discussionContainer);
       }
 
-      if (typeof gl.diffNotesCompileComponents !== 'undefined' && note.discussion_resolvable) {
+      if (typeof gl.diffNotesCompileComponents !== 'undefined' && noteEntity.discussion_resolvable) {
         gl.diffNotesCompileComponents();
-        this.renderDiscussionAvatar(diffAvatarContainer, note);
+        this.renderDiscussionAvatar(diffAvatarContainer, noteEntity);
       }
 
       gl.utils.localTimeAgo($('.js-timeago'), false);
@@ -397,13 +442,13 @@ require('./task_list');
         .get(0);
     };
 
-    Notes.prototype.renderDiscussionAvatar = function(diffAvatarContainer, note) {
+    Notes.prototype.renderDiscussionAvatar = function(diffAvatarContainer, noteEntity) {
       var commentButton = diffAvatarContainer.find('.js-add-diff-note-button');
       var avatarHolder = diffAvatarContainer.find('.diff-comment-avatar-holders');
 
       if (!avatarHolder.length) {
         avatarHolder = document.createElement('diff-note-avatars');
-        avatarHolder.setAttribute('discussion-id', note.discussion_id);
+        avatarHolder.setAttribute('discussion-id', noteEntity.discussion_id);
 
         diffAvatarContainer.append(avatarHolder);
 
@@ -550,16 +595,16 @@ require('./task_list');
     Updates the current note field.
      */
 
-    Notes.prototype.updateNote = function(_xhr, note, _status) {
+    Notes.prototype.updateNote = function(_xhr, noteEntity, _status) {
       var $html, $note_li;
       // Convert returned HTML to a jQuery object so we can modify it further
-      $html = $(note.html);
+      $html = $(noteEntity.html);
       this.revertNoteEditForm();
       gl.utils.localTimeAgo($('.js-timeago', $html));
       $html.renderGFM();
       $html.find('.js-task-list-container').taskList('enable');
       // Find the note's `li` element by ID and replace it with the updated HTML
-      $note_li = $('.note-row-' + note.id);
+      $note_li = $('.note-row-' + noteEntity.id);
 
       $note_li.replaceWith($html);
 
@@ -570,7 +615,7 @@ require('./task_list');
 
     Notes.prototype.checkContentToAllowEditing = function($el) {
       var initialContent = $el.find('.original-note-content').text().trim();
-      var currentContent = $el.find('.note-textarea').val();
+      var currentContent = $el.find('.js-note-text').val();
       var isAllowed = true;
 
       if (currentContent === initialContent) {
@@ -584,7 +629,7 @@ require('./task_list');
           gl.utils.scrollToElement($el);
         }
 
-        $el.find('.js-edit-warning').show();
+        $el.find('.js-finish-edit-warning').show();
         isAllowed = false;
       }
 
@@ -603,7 +648,7 @@ require('./task_list');
       var $target = $(e.target);
       var $editForm = $(this.getEditFormSelector($target));
       var $note = $target.closest('.note');
-      var $currentlyEditing = $('.note.is-editting:visible');
+      var $currentlyEditing = $('.note.is-editing:visible');
 
       if ($currentlyEditing.length) {
         var isEditAllowed = this.checkContentToAllowEditing($currentlyEditing);
@@ -615,7 +660,7 @@ require('./task_list');
 
       $note.find('.js-note-attachment-delete').show();
       $editForm.addClass('current-note-edit-form');
-      $note.addClass('is-editting');
+      $note.addClass('is-editing');
       this.putEditFormInPlace($target);
     };
 
@@ -627,21 +672,34 @@ require('./task_list');
 
     Notes.prototype.cancelEdit = function(e) {
       e.preventDefault();
-      var $target = $(e.target);
-      var note = $target.closest('.note');
-      note.find('.js-edit-warning').hide();
+      const $target = $(e.target);
+      const $note = $target.closest('.note');
+      const noteId = $note.attr('data-note-id');
+
       this.revertNoteEditForm($target);
-      return this.removeNoteEditForm(note);
+
+      if (this.updatedNotesTrackingMap[noteId]) {
+        const $newNote = $(this.updatedNotesTrackingMap[noteId].html);
+        $note.replaceWith($newNote);
+        this.updatedNotesTrackingMap[noteId] = null;
+
+        // Update datetime format on the recent note
+        gl.utils.localTimeAgo($newNote.find('.js-timeago'), false);
+      }
+      else {
+        $note.find('.js-finish-edit-warning').hide();
+        this.removeNoteEditForm($note);
+      }
     };
 
     Notes.prototype.revertNoteEditForm = function($target) {
-      $target = $target || $('.note.is-editting:visible');
+      $target = $target || $('.note.is-editing:visible');
       var selector = this.getEditFormSelector($target);
       var $editForm = $(selector);
 
       $editForm.insertBefore('.notes-form');
       $editForm.find('.js-comment-button').enable();
-      $editForm.find('.js-edit-warning').hide();
+      $editForm.find('.js-finish-edit-warning').hide();
     };
 
     Notes.prototype.getEditFormSelector = function($el) {
@@ -654,11 +712,11 @@ require('./task_list');
       return selector;
     };
 
-    Notes.prototype.removeNoteEditForm = function(note) {
-      var form = note.find('.current-note-edit-form');
-      note.removeClass('is-editting');
+    Notes.prototype.removeNoteEditForm = function($note) {
+      var form = $note.find('.current-note-edit-form');
+      $note.removeClass('is-editing');
       form.removeClass('current-note-edit-form');
-      form.find('.js-edit-warning').hide();
+      form.find('.js-finish-edit-warning').hide();
       // Replace markdown textarea text with original note text.
       return form.find('.js-note-text').val(form.find('form.edit-note').data('original-note'));
     };
@@ -683,9 +741,9 @@ require('./task_list');
         // to remove all. Using $(".note[id='noteId']") ensure we get all the notes,
         // where $("#noteId") would return only one.
         return function(i, el) {
-          var note, notes;
-          note = $(el);
-          notes = note.closest(".discussion-notes");
+          var $note, $notes;
+          $note = $(el);
+          $notes = $note.closest(".discussion-notes");
 
           if (typeof gl.diffNotesCompileComponents !== 'undefined') {
             if (gl.diffNoteApps[noteElId]) {
@@ -693,18 +751,18 @@ require('./task_list');
             }
           }
 
-          note.remove();
+          $note.remove();
 
           // check if this is the last note for this line
-          if (notes.find(".note").length === 0) {
-            var notesTr = notes.closest("tr");
+          if ($notes.find(".note").length === 0) {
+            var notesTr = $notes.closest("tr");
 
             // "Discussions" tab
-            notes.closest(".timeline-entry").remove();
+            $notes.closest(".timeline-entry").remove();
 
             // The notes tr can contain multiple lists of notes, like on the parallel diff
             if (notesTr.find('.discussion-notes').length > 1) {
-              notes.remove();
+              $notes.remove();
             } else {
               notesTr.remove();
             }
@@ -723,12 +781,11 @@ require('./task_list');
      */
 
     Notes.prototype.removeAttachment = function() {
-      var note;
-      note = $(this).closest(".note");
-      note.find(".note-attachment").remove();
-      note.find(".note-body > .note-text").show();
-      note.find(".note-header").show();
-      return note.find(".current-note-edit-form").remove();
+      const $note = $(this).closest(".note");
+      $note.find(".note-attachment").remove();
+      $note.find(".note-body > .note-text").show();
+      $note.find(".note-header").show();
+      return $note.find(".current-note-edit-form").remove();
     };
 
     /*
@@ -1004,6 +1061,19 @@ require('./task_list');
       $editForm.find('.referenced-users').hide();
     };
 
+    Notes.prototype.putConflictEditWarningInPlace = function(noteEntity, $note) {
+      if ($note.find('.js-conflict-edit-warning').length === 0) {
+        const $alert = $(`<div class="js-conflict-edit-warning alert alert-danger">
+          This comment has changed since you started editing, please review the
+          <a href="#note_${noteEntity.id}" target="_blank" rel="noopener noreferrer">
+            updated comment
+          </a>
+          to ensure information is not lost
+        </div>`);
+        $alert.insertAfter($note.find('.note-text'));
+      }
+    };
+
     Notes.prototype.updateNotesCount = function(updateCount) {
       return this.notesCountBadge.text(parseInt(this.notesCountBadge.text(), 10) + updateCount);
     };
@@ -1064,11 +1134,20 @@ require('./task_list');
       return $form;
     };
 
-    Notes.animateAppendNote = function(noteHTML, $notesList) {
-      const $note = window.$(noteHTML);
+    Notes.animateAppendNote = function(noteHtml, $notesList) {
+      const $note = $(noteHtml);
 
       $note.addClass('fade-in').renderGFM();
       $notesList.append($note);
+      return $note;
+    };
+
+    Notes.animateUpdateNote = function(noteHtml, $note) {
+      const $updatedNote = $(noteHtml);
+
+      $updatedNote.addClass('fade-in').renderGFM();
+      $note.replaceWith($updatedNote);
+      return $updatedNote;
     };
 
     return Notes;
diff --git a/app/assets/stylesheets/pages/notes.scss b/app/assets/stylesheets/pages/notes.scss
index 7cf74502a3a..f89150ebead 100644
--- a/app/assets/stylesheets/pages/notes.scss
+++ b/app/assets/stylesheets/pages/notes.scss
@@ -67,7 +67,7 @@ ul.notes {
       }
     }
 
-    &.is-editting {
+    &.is-editing {
       .note-header,
       .note-text,
       .edited-text {
diff --git a/app/views/projects/notes/_edit_form.html.haml b/app/views/projects/notes/_edit_form.html.haml
index 8b4e5928e0d..a1efc0b051a 100644
--- a/app/views/projects/notes/_edit_form.html.haml
+++ b/app/views/projects/notes/_edit_form.html.haml
@@ -7,7 +7,7 @@
       = render 'projects/notes/hints'
 
     .note-form-actions.clearfix
-      .settings-message.note-edit-warning.js-edit-warning
+      .settings-message.note-edit-warning.js-finish-edit-warning
         Finish editing this message first!
       = submit_tag 'Save comment', class: 'btn btn-nr btn-save js-comment-button'
       %button.btn.btn-nr.btn-cancel.note-edit-cancel{ type: 'button' }
diff --git a/app/views/shared/notes/_note.html.haml b/app/views/shared/notes/_note.html.haml
index 731270d4127..9657b4eea82 100644
--- a/app/views/shared/notes/_note.html.haml
+++ b/app/views/shared/notes/_note.html.haml
@@ -2,7 +2,11 @@
 - return if note.cross_reference_not_visible_for?(current_user)
 
 - note_editable = note_editable?(note)
-%li.timeline-entry{ id: dom_id(note), class: ["note", "note-row-#{note.id}", ('system-note' if note.system)], data: {author_id: note.author.id, editable: note_editable, note_id: note.id} }
+%li.timeline-entry{ id: dom_id(note),
+  class: ["note", "note-row-#{note.id}", ('system-note' if note.system)],
+  data: { author_id: note.author.id,
+    editable: note_editable,
+    note_id: note.id } }
   .timeline-entry-inner
     .timeline-icon
       - if note.system
diff --git a/changelogs/unreleased/30458-real-time-note-edits.yml b/changelogs/unreleased/30458-real-time-note-edits.yml
new file mode 100644
index 00000000000..f67348c5302
--- /dev/null
+++ b/changelogs/unreleased/30458-real-time-note-edits.yml
@@ -0,0 +1,4 @@
+---
+title: Update note edits in real-time
+merge_request:
+author:
diff --git a/spec/features/gitlab_flavored_markdown_spec.rb b/spec/features/gitlab_flavored_markdown_spec.rb
index 01b1aee4fd3..f5b54463df8 100644
--- a/spec/features/gitlab_flavored_markdown_spec.rb
+++ b/spec/features/gitlab_flavored_markdown_spec.rb
@@ -62,6 +62,8 @@ describe "GitLab Flavored Markdown", feature: true do
                       project: project,
                       title: "fix #{@other_issue.to_reference}",
                       description: "ask #{fred.to_reference} for details")
+
+      @note = create(:note_on_issue, noteable: @issue, project: @issue.project, note: "Hello world")
     end
 
     it "renders subject in issues#index" do
@@ -81,14 +83,6 @@ describe "GitLab Flavored Markdown", feature: true do
 
       expect(page).to have_link(fred.to_reference)
     end
-
-    it "renders updated subject once edited somewhere else in issues#show" do
-      visit namespace_project_issue_path(project.namespace, project, @issue)
-      @issue.update(title: "fix #{@other_issue.to_reference} and update")
-
-      wait_for_vue_resource
-      expect(page).to have_text("fix #{@other_issue.to_reference} and update")
-    end
   end
 
   describe "for merge requests" do
diff --git a/spec/features/issues/note_polling_spec.rb b/spec/features/issues/note_polling_spec.rb
index 378f6de1a78..58b3215f14c 100644
--- a/spec/features/issues/note_polling_spec.rb
+++ b/spec/features/issues/note_polling_spec.rb
@@ -4,14 +4,77 @@ feature 'Issue notes polling', :feature, :js do
   let(:project) { create(:empty_project, :public) }
   let(:issue) { create(:issue, project: project) }
 
-  before do
-    visit namespace_project_issue_path(project.namespace, project, issue)
+  describe 'creates' do
+    before do
+      visit namespace_project_issue_path(project.namespace, project, issue)
+    end
+
+    it 'displays the new comment' do
+      note = create(:note, noteable: issue, project: project, note: 'Looks good!')
+      page.execute_script('notes.refresh();')
+
+      expect(page).to have_selector("#note_#{note.id}", text: 'Looks good!')
+    end
   end
 
-  it 'should display the new comment' do
-    note = create(:note, noteable: issue, project: project, note: 'Looks good!')
-    page.execute_script('notes.refresh();')
+  describe 'updates' do
+    let(:user) { create(:user) }
+    let(:note_text) { "Hello World" }
+    let(:updated_text) { "Bye World" }
+    let!(:existing_note) { create(:note, noteable: issue, project: project, author: user, note: note_text) }
+
+    before do
+      login_as(user)
+      visit namespace_project_issue_path(project.namespace, project, issue)
+    end
+
+    it 'displays the updated content' do
+      expect(page).to have_selector("#note_#{existing_note.id}", text: note_text)
+
+      update_note(existing_note, updated_text)
+
+      expect(page).to have_selector("#note_#{existing_note.id}", text: updated_text)
+    end
+
+    it 'when editing but have not changed anything, and an update comes in, show the updated content in the textarea' do
+      find("#note_#{existing_note.id} .js-note-edit").click
+
+      expect(page).to have_field("note[note]", with: note_text)
+
+      update_note(existing_note, updated_text)
+
+      expect(page).to have_field("note[note]", with: updated_text)
+    end
+
+    it 'when editing but you changed some things, and an update comes in, show a warning' do
+      find("#note_#{existing_note.id} .js-note-edit").click
 
-    expect(page).to have_selector("#note_#{note.id}", text: 'Looks good!')
+      expect(page).to have_field("note[note]", with: note_text)
+
+      find("#note_#{existing_note.id} .js-note-text").set('something random')
+
+      update_note(existing_note, updated_text)
+
+      expect(page).to have_selector(".alert")
+    end
+
+    it 'when editing but you changed some things, an update comes in, and you press cancel, show the updated content' do
+      find("#note_#{existing_note.id} .js-note-edit").click
+
+      expect(page).to have_field("note[note]", with: note_text)
+
+      find("#note_#{existing_note.id} .js-note-text").set('something random')
+
+      update_note(existing_note, updated_text)
+
+      find("#note_#{existing_note.id} .note-edit-cancel").click
+
+      expect(page).to have_selector("#note_#{existing_note.id}", text: updated_text)
+    end
+  end
+
+  def update_note(note, new_text)
+    note.update(note: new_text)
+    page.execute_script('notes.refresh();')
   end
 end
diff --git a/spec/javascripts/notes_spec.js b/spec/javascripts/notes_spec.js
index ca8ee04d955..cdc5c4510ff 100644
--- a/spec/javascripts/notes_spec.js
+++ b/spec/javascripts/notes_spec.js
@@ -1,10 +1,12 @@
 /* eslint-disable space-before-function-paren, no-unused-expressions, no-var, object-shorthand, comma-dangle, max-len */
 /* global Notes */
 
-require('~/notes');
-require('vendor/autosize');
-require('~/gl_form');
-require('~/lib/utils/text_utility');
+import 'vendor/autosize';
+import '~/gl_form';
+import '~/lib/utils/text_utility';
+import '~/render_gfm';
+import '~/render_math';
+import '~/notes';
 
 (function() {
   window.gon || (window.gon = {});
@@ -80,35 +82,78 @@ require('~/lib/utils/text_utility');
 
       beforeEach(() => {
         note = {
+          id: 1,
           discussion_html: null,
           valid: true,
-          html: '<div></div>',
+          note: 'heya',
+          html: '<div>heya</div>',
         };
-        $notesList = jasmine.createSpyObj('$notesList', ['find']);
+        $notesList = jasmine.createSpyObj('$notesList', [
+          'find',
+          'append',
+        ]);
 
         notes = jasmine.createSpyObj('notes', [
           'refresh',
           'isNewNote',
+          'isUpdatedNote',
           'collapseLongCommitList',
           'updateNotesCount',
+          'putConflictEditWarningInPlace'
         ]);
         notes.taskList = jasmine.createSpyObj('tasklist', ['init']);
         notes.note_ids = [];
+        notes.updatedNotesTrackingMap = {};
 
-        spyOn(window, '$').and.returnValue($notesList);
         spyOn(gl.utils, 'localTimeAgo');
-        spyOn(Notes, 'animateAppendNote');
-        notes.isNewNote.and.returnValue(true);
-
-        Notes.prototype.renderNote.call(notes, note);
+        spyOn(Notes, 'animateAppendNote').and.callThrough();
+        spyOn(Notes, 'animateUpdateNote').and.callThrough();
       });
 
-      it('should query for the notes list', () => {
-        expect(window.$).toHaveBeenCalledWith('ul.main-notes-list');
+      describe('when adding note', () => {
+        it('should call .animateAppendNote', () => {
+          notes.isNewNote.and.returnValue(true);
+          Notes.prototype.renderNote.call(notes, note, null, $notesList);
+
+          expect(Notes.animateAppendNote).toHaveBeenCalledWith(note.html, $notesList);
+        });
       });
 
-      it('should call .animateAppendNote', () => {
-        expect(Notes.animateAppendNote).toHaveBeenCalledWith(note.html, $notesList);
+      describe('when note was edited', () => {
+        it('should call .animateUpdateNote', () => {
+          notes.isUpdatedNote.and.returnValue(true);
+          const $note = $('<div>');
+          $notesList.find.and.returnValue($note);
+          Notes.prototype.renderNote.call(notes, note, null, $notesList);
+
+          expect(Notes.animateUpdateNote).toHaveBeenCalledWith(note.html, $note);
+        });
+
+        describe('while editing', () => {
+          it('should update textarea if nothing has been touched', () => {
+            notes.isUpdatedNote.and.returnValue(true);
+            const $note = $(`<div class="is-editing">
+              <div class="original-note-content">initial</div>
+              <textarea class="js-note-text">initial</textarea>
+            </div>`);
+            $notesList.find.and.returnValue($note);
+            Notes.prototype.renderNote.call(notes, note, null, $notesList);
+
+            expect($note.find('.js-note-text').val()).toEqual(note.note);
+          });
+
+          it('should call .putConflictEditWarningInPlace', () => {
+            notes.isUpdatedNote.and.returnValue(true);
+            const $note = $(`<div class="is-editing">
+              <div class="original-note-content">initial</div>
+              <textarea class="js-note-text">different</textarea>
+            </div>`);
+            $notesList.find.and.returnValue($note);
+            Notes.prototype.renderNote.call(notes, note, null, $notesList);
+
+            expect(notes.putConflictEditWarningInPlace).toHaveBeenCalledWith(note, $note);
+          });
+        });
       });
     });
 
@@ -147,14 +192,12 @@ require('~/lib/utils/text_utility');
       });
 
       describe('Discussion root note', () => {
-        let $notesList;
         let body;
 
         beforeEach(() => {
           body = jasmine.createSpyObj('body', ['attr']);
           discussionContainer = { length: 0 };
 
-          spyOn(window, '$').and.returnValues(discussionContainer, body, $notesList);
           $form.closest.and.returnValues(row, $form);
           $form.find.and.returnValues(discussionContainer);
           body.attr.and.returnValue('');
@@ -162,12 +205,8 @@ require('~/lib/utils/text_utility');
           Notes.prototype.renderDiscussionNote.call(notes, note, $form);
         });
 
-        it('should query for the notes list', () => {
-          expect(window.$.calls.argsFor(2)).toEqual(['ul.main-notes-list']);
-        });
-
         it('should call Notes.animateAppendNote', () => {
-          expect(Notes.animateAppendNote).toHaveBeenCalledWith(note.discussion_html, $notesList);
+          expect(Notes.animateAppendNote).toHaveBeenCalledWith(note.discussion_html, $('.main-notes-list'));
         });
       });
 
@@ -175,16 +214,12 @@ require('~/lib/utils/text_utility');
         beforeEach(() => {
           discussionContainer = { length: 1 };
 
-          spyOn(window, '$').and.returnValues(discussionContainer);
-          $form.closest.and.returnValues(row);
+          $form.closest.and.returnValues(row, $form);
+          $form.find.and.returnValues(discussionContainer);
 
           Notes.prototype.renderDiscussionNote.call(notes, note, $form);
         });
 
-        it('should query foor the discussion container', () => {
-          expect(window.$).toHaveBeenCalledWith(`.notes[data-discussion-id="${note.discussion_id}"]`);
-        });
-
         it('should call Notes.animateAppendNote', () => {
           expect(Notes.animateAppendNote).toHaveBeenCalledWith(note.html, discussionContainer);
         });
@@ -193,35 +228,45 @@ require('~/lib/utils/text_utility');
 
     describe('animateAppendNote', () => {
       let noteHTML;
-      let $note;
       let $notesList;
+      let $resultantNote;
 
       beforeEach(() => {
         noteHTML = '<div></div>';
-        $note = jasmine.createSpyObj('$note', ['addClass', 'renderGFM', 'removeClass']);
         $notesList = jasmine.createSpyObj('$notesList', ['append']);
 
-        spyOn(window, '$').and.returnValue($note);
-        spyOn(window, 'setTimeout').and.callThrough();
-        $note.addClass.and.returnValue($note);
-        $note.renderGFM.and.returnValue($note);
+        $resultantNote = Notes.animateAppendNote(noteHTML, $notesList);
+      });
 
-        Notes.animateAppendNote(noteHTML, $notesList);
+      it('should have `fade-in` class', () => {
+        expect($resultantNote.hasClass('fade-in')).toEqual(true);
       });
 
-      it('should init the note jquery object', () => {
-        expect(window.$).toHaveBeenCalledWith(noteHTML);
+      it('should append note to the notes list', () => {
+        expect($notesList.append).toHaveBeenCalledWith($resultantNote);
       });
+    });
+
+    describe('animateUpdateNote', () => {
+      let noteHTML;
+      let $note;
+      let $updatedNote;
 
-      it('should call addClass', () => {
-        expect($note.addClass).toHaveBeenCalledWith('fade-in');
+      beforeEach(() => {
+        noteHTML = '<div></div>';
+        $note = jasmine.createSpyObj('$note', [
+          'replaceWith'
+        ]);
+
+        $updatedNote = Notes.animateUpdateNote(noteHTML, $note);
       });
-      it('should call renderGFM', () => {
-        expect($note.renderGFM).toHaveBeenCalledWith();
+
+      it('should have `fade-in` class', () => {
+        expect($updatedNote.hasClass('fade-in')).toEqual(true);
       });
 
-      it('should append note to the notes list', () => {
-        expect($notesList.append).toHaveBeenCalledWith($note);
+      it('should call replaceWith on $note', () => {
+        expect($note.replaceWith).toHaveBeenCalledWith($updatedNote);
       });
     });
   });