Re-implemented image commenting on diffs

This re-implements image commenting in merge request diffs.
This feature was previously lost when the merge request
page was refactored into Vue.

With this, we create an overlay component. The overlay
component handles displaying the comment badges
and the comment form badge.
Badges are displayed based on the position attribute
sent with the discussion.

Comment forms for diff files are controlled through
a different state property. This is so we don't
tie comment forms to diff files directly creating
deep nested state. Instead we create a flat array
which holds the file hash & the X & Y position of
the comment form.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/48956

3 files changed, 237 insertions, 13 deletions

diff --git a/spec/javascripts/diffs/components/diff_content_spec.js b/spec/javascripts/diffs/components/diff_content_spec.js
index 67f7b569f47..a31e04d426b 100644
--- a/spec/javascripts/diffs/components/diff_content_spec.js
+++ b/spec/javascripts/diffs/components/diff_content_spec.js
@@ -1,15 +1,24 @@
 import Vue from 'vue';
 import DiffContentComponent from '~/diffs/components/diff_content.vue';
-import store from '~/mr_notes/stores';
+import { createStore } from '~/mr_notes/stores';
 import { mountComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
 import { GREEN_BOX_IMAGE_URL, RED_BOX_IMAGE_URL } from 'spec/test_constants';
+import '~/behaviors/markdown/render_gfm';
 import diffFileMockData from '../mock_data/diff_file';
+import discussionsMockData from '../mock_data/diff_discussions';
 
 describe('DiffContent', () => {
   const Component = Vue.extend(DiffContentComponent);
   let vm;
 
   beforeEach(() => {
+    const store = createStore();
+    store.state.notes.noteableData = {
+      current_user: {
+        can_create_note: false,
+      },
+    };
+
     vm = mountComponentWithStore(Component, {
       store,
       props: {
@@ -46,21 +55,49 @@ describe('DiffContent', () => {
     });
 
     describe('image diff', () => {
-      beforeEach(() => {
+      beforeEach(done => {
         vm.diffFile.newPath = GREEN_BOX_IMAGE_URL;
         vm.diffFile.newSha = 'DEF';
         vm.diffFile.oldPath = RED_BOX_IMAGE_URL;
         vm.diffFile.oldSha = 'ABC';
         vm.diffFile.viewPath = '';
+        vm.diffFile.discussions = [{ ...discussionsMockData }];
+        vm.$store.state.diffs.commentForms.push({ fileHash: vm.diffFile.fileHash, x: 10, y: 20 });
+
+        vm.$nextTick(done);
       });
 
-      it('should have image diff view in place', done => {
-        vm.$nextTick(() => {
-          expect(vm.$el.querySelectorAll('.js-diff-inline-view').length).toEqual(0);
+      it('should have image diff view in place', () => {
+        expect(vm.$el.querySelectorAll('.js-diff-inline-view').length).toEqual(0);
+
+        expect(vm.$el.querySelectorAll('.diff-viewer .image').length).toEqual(1);
+      });
 
-          expect(vm.$el.querySelectorAll('.diff-viewer .image').length).toEqual(1);
+      it('renders image diff overlay', () => {
+        expect(vm.$el.querySelector('.image-diff-overlay')).not.toBe(null);
+      });
 
-          done();
+      it('renders diff file discussions', () => {
+        expect(vm.$el.querySelectorAll('.discussion .note.timeline-entry').length).toEqual(5);
+      });
+
+      describe('handleSaveNote', () => {
+        it('dispatches handleSaveNote', () => {
+          spyOn(vm.$store, 'dispatch').and.stub();
+
+          vm.handleSaveNote('test');
+
+          expect(vm.$store.dispatch).toHaveBeenCalledWith('diffs/saveDiffDiscussion', {
+            note: 'test',
+            formData: {
+              noteableData: jasmine.anything(),
+              noteableType: jasmine.anything(),
+              diffFile: vm.diffFile,
+              positionType: 'image',
+              x: 10,
+              y: 20,
+            },
+          });
         });
       });
     });
diff --git a/spec/javascripts/diffs/components/diff_discussions_spec.js b/spec/javascripts/diffs/components/diff_discussions_spec.js
index 270f363825f..0bc9da5ad0f 100644
--- a/spec/javascripts/diffs/components/diff_discussions_spec.js
+++ b/spec/javascripts/diffs/components/diff_discussions_spec.js
@@ -1,24 +1,90 @@
 import Vue from 'vue';
 import DiffDiscussions from '~/diffs/components/diff_discussions.vue';
-import store from '~/mr_notes/stores';
+import { createStore } from '~/mr_notes/stores';
 import { createComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
+import '~/behaviors/markdown/render_gfm';
 import discussionsMockData from '../mock_data/diff_discussions';
 
 describe('DiffDiscussions', () => {
-  let component;
+  let vm;
   const getDiscussionsMockData = () => [Object.assign({}, discussionsMockData)];
 
-  beforeEach(() => {
-    component = createComponentWithStore(Vue.extend(DiffDiscussions), store, {
+  function createComponent(props = {}) {
+    const store = createStore();
+
+    vm = createComponentWithStore(Vue.extend(DiffDiscussions), store, {
       discussions: getDiscussionsMockData(),
+      ...props,
     }).$mount();
+  }
+
+  afterEach(() => {
+    vm.$destroy();
   });
 
   describe('template', () => {
     it('should have notes list', () => {
-      const { $el } = component;
+      createComponent();
+
+      expect(vm.$el.querySelectorAll('.discussion .note.timeline-entry').length).toEqual(5);
+    });
+  });
+
+  describe('image commenting', () => {
+    it('renders collapsible discussion button', () => {
+      createComponent({ shouldCollapseDiscussions: true });
+
+      expect(vm.$el.querySelector('.js-diff-notes-toggle')).not.toBe(null);
+      expect(vm.$el.querySelector('.js-diff-notes-toggle svg')).not.toBe(null);
+      expect(vm.$el.querySelector('.js-diff-notes-toggle').classList).toContain(
+        'diff-notes-collapse',
+      );
+    });
+
+    it('dispatches toggleDiscussion when clicking collapse button', () => {
+      createComponent({ shouldCollapseDiscussions: true });
+
+      spyOn(vm.$store, 'dispatch').and.stub();
+
+      vm.$el.querySelector('.js-diff-notes-toggle').click();
+
+      expect(vm.$store.dispatch).toHaveBeenCalledWith('toggleDiscussion', {
+        discussionId: vm.discussions[0].id,
+      });
+    });
+
+    it('renders expand button when discussion is collapsed', done => {
+      createComponent({ shouldCollapseDiscussions: true });
+
+      vm.discussions[0].expanded = false;
+
+      vm.$nextTick(() => {
+        expect(vm.$el.querySelector('.js-diff-notes-toggle').textContent.trim()).toBe('1');
+        expect(vm.$el.querySelector('.js-diff-notes-toggle').className).toContain(
+          'btn-transparent badge badge-pill',
+        );
+
+        done();
+      });
+    });
+
+    it('hides discussion when collapsed', done => {
+      createComponent({ shouldCollapseDiscussions: true });
+
+      vm.discussions[0].expanded = false;
+
+      vm.$nextTick(() => {
+        expect(vm.$el.querySelector('.note-discussion').style.display).toBe('none');
+
+        done();
+      });
+    });
+
+    it('renders badge on avatar', () => {
+      createComponent({ renderAvatarBadge: true, discussions: [{ ...discussionsMockData }] });
 
-      expect($el.querySelectorAll('.discussion .note.timeline-entry').length).toEqual(5);
+      expect(vm.$el.querySelector('.user-avatar-link .badge-pill')).not.toBe(null);
+      expect(vm.$el.querySelector('.user-avatar-link .badge-pill').textContent.trim()).toBe('1');
     });
   });
 });
diff --git a/spec/javascripts/diffs/components/image_diff_overlay_spec.js b/spec/javascripts/diffs/components/image_diff_overlay_spec.js
new file mode 100644
index 00000000000..4ab5ebd6c01
--- /dev/null
+++ b/spec/javascripts/diffs/components/image_diff_overlay_spec.js
@@ -0,0 +1,121 @@
+import Vue from 'vue';
+import ImageDiffOverlay from '~/diffs/components/image_diff_overlay.vue';
+import { createStore } from '~/mr_notes/stores';
+import { mountComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
+import { imageDiffDiscussions } from '../mock_data/diff_discussions';
+
+describe('Diffs image diff overlay component', () => {
+  let Component;
+  let vm;
+
+  function createComponent(props = {}, extendStore = () => {}) {
+    const store = createStore();
+
+    extendStore(store);
+
+    vm = mountComponentWithStore(Component, {
+      store,
+      props: { discussions: [...imageDiffDiscussions], fileHash: 'ABC', ...props },
+    });
+  }
+
+  beforeAll(() => {
+    Component = Vue.extend(ImageDiffOverlay);
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  it('renders comment badges', () => {
+    createComponent();
+
+    expect(vm.$el.querySelectorAll('.js-image-badge').length).toBe(2);
+  });
+
+  it('renders index of discussion in badge', () => {
+    createComponent();
+
+    expect(vm.$el.querySelectorAll('.js-image-badge')[0].textContent.trim()).toBe('1');
+    expect(vm.$el.querySelectorAll('.js-image-badge')[1].textContent.trim()).toBe('2');
+  });
+
+  it('renders icon when showCommentIcon is true', () => {
+    createComponent({ showCommentIcon: true });
+
+    expect(vm.$el.querySelector('.js-image-badge svg')).not.toBe(null);
+  });
+
+  it('sets badge comment positions', () => {
+    createComponent();
+
+    expect(vm.$el.querySelectorAll('.js-image-badge')[0].style.left).toBe('10px');
+    expect(vm.$el.querySelectorAll('.js-image-badge')[0].style.top).toBe('10px');
+
+    expect(vm.$el.querySelectorAll('.js-image-badge')[1].style.left).toBe('5px');
+    expect(vm.$el.querySelectorAll('.js-image-badge')[1].style.top).toBe('5px');
+  });
+
+  it('renders single badge for discussion object', () => {
+    createComponent({
+      discussions: {
+        ...imageDiffDiscussions[0],
+      },
+    });
+
+    expect(vm.$el.querySelectorAll('.js-image-badge').length).toBe(1);
+  });
+
+  it('dispatches openDiffFileCommentForm when clcking overlay', () => {
+    createComponent({ canComment: true });
+
+    spyOn(vm.$store, 'dispatch').and.stub();
+
+    vm.$el.querySelector('.js-add-image-diff-note-button').click();
+
+    expect(vm.$store.dispatch).toHaveBeenCalledWith('diffs/openDiffFileCommentForm', {
+      fileHash: 'ABC',
+      x: 0,
+      y: 0,
+    });
+  });
+
+  describe('toggle discussion', () => {
+    it('disables buttons when shouldToggleDiscussion is false', () => {
+      createComponent({ shouldToggleDiscussion: false });
+
+      expect(vm.$el.querySelector('.js-image-badge').hasAttribute('disabled')).toBe(true);
+    });
+
+    it('dispatches toggleDiscussion when clicking image badge', () => {
+      createComponent();
+
+      spyOn(vm.$store, 'dispatch').and.stub();
+
+      vm.$el.querySelector('.js-image-badge').click();
+
+      expect(vm.$store.dispatch).toHaveBeenCalledWith('toggleDiscussion', { discussionId: '1' });
+    });
+  });
+
+  describe('comment form', () => {
+    beforeEach(() => {
+      createComponent({}, store => {
+        store.state.diffs.commentForms.push({
+          fileHash: 'ABC',
+          x: 20,
+          y: 10,
+        });
+      });
+    });
+
+    it('renders comment form badge', () => {
+      expect(vm.$el.querySelector('.comment-indicator')).not.toBe(null);
+    });
+
+    it('sets comment form badge position', () => {
+      expect(vm.$el.querySelector('.comment-indicator').style.left).toBe('20px');
+      expect(vm.$el.querySelector('.comment-indicator').style.top).toBe('10px');
+    });
+  });
+});