Clean up swimlanes_buffered_rendering-feature feature flag

Uses VirtualList to load epic swimlanes
Changelog: changed
EE: true

app/controllers/groups/boards_controller.rb

@@ -9,7 +9,6 @@ class Groups::BoardsController < Groups::ApplicationController
   before_action do
     push_frontend_feature_flag(:issue_boards_filtered_search, group, default_enabled: :yaml)
     push_frontend_feature_flag(:board_multi_select, group, default_enabled: :yaml)
-    push_frontend_feature_flag(:swimlanes_buffered_rendering, group, default_enabled: :yaml)
     push_frontend_feature_flag(:iteration_cadences, group, default_enabled: :yaml)
     experiment(:prominent_create_board_btn, subject: current_user) do |e|
       e.use { }

app/controllers/projects/boards_controller.rb

@@ -7,7 +7,6 @@ class Projects::BoardsController < Projects::ApplicationController
   before_action :check_issues_available!
   before_action :assign_endpoint_vars
   before_action do
-    push_frontend_feature_flag(:swimlanes_buffered_rendering, project, default_enabled: :yaml)
     push_frontend_feature_flag(:issue_boards_filtered_search, project&.group, default_enabled: :yaml)
     push_frontend_feature_flag(:board_multi_select, project, default_enabled: :yaml)
     push_frontend_feature_flag(:iteration_cadences, project&.group, default_enabled: :yaml)

config/feature_flags/development/swimlanes_buffered_rendering.yml

----
-name: swimlanes_buffered_rendering
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56614
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/324994
-milestone: '13.11'
-type: development
-group: group::product planning
-default_enabled: false
\ No newline at end of file

ee/app/assets/javascripts/boards/components/epics_swimlanes.vue

@@ -9,7 +9,6 @@ import { isListDraggable } from '~/boards/boards_util';
 import eventHub from '~/boards/eventhub';
 import { s__, n__, __ } from '~/locale';
 import defaultSortableConfig from '~/sortable/sortable_config';
-import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 import { calculateSwimlanesBufferSize } from '../boards_util';
 import { DRAGGABLE_TAG, EPIC_LANE_BASE_HEIGHT, DraggableItemTypes } from '../constants';
 import EpicLane from './epic_lane.vue';
@@ -33,7 +32,6 @@ export default {
   directives: {
     GlTooltip: GlTooltipDirective,
   },
-  mixins: [glFeatureFlagsMixin()],
   props: {
     lists: {
       type: Array,
@@ -227,28 +225,16 @@ export default {
         </div>
       </component>
       <div class="board-epics-swimlanes gl-display-table">
-        <template v-if="glFeatures.swimlanesBufferedRendering">
-          <virtual-list
-            v-if="epics.length"
-            :size="$options.epicLaneBaseHeight"
-            :remain="bufferSize"
-            :bench="bufferSize"
-            :scrollelement="$refs.scrollableContainer"
-            :item="$options.EpicLane"
-            :itemcount="epics.length"
-            :itemprops="getEpicLaneProps"
-          />
-        </template>
-        <template v-else>
-          <epic-lane
-            v-for="epic in epics"
-            :key="epic.id"
-            :epic="epic"
-            :lists="lists"
-            :disabled="disabled"
-            :can-admin-list="canAdminList"
-          />
-        </template>
+        <virtual-list
+          v-if="epics.length"
+          :size="$options.epicLaneBaseHeight"
+          :remain="bufferSize"
+          :bench="bufferSize"
+          :scrollelement="$refs.scrollableContainer"
+          :item="$options.EpicLane"
+          :itemcount="epics.length"
+          :itemprops="getEpicLaneProps"
+        />
         <div v-if="hasMoreEpics" class="swimlanes-button gl-pb-3 gl-pl-3 gl-sticky gl-left-0">
           <gl-button
             category="tertiary"

ee/spec/frontend/boards/components/epics_swimlanes_spec.js

@@ -4,7 +4,7 @@ import Vue from 'vue';
 import VirtualList from 'vue-virtual-scroll-list';
 import Draggable from 'vuedraggable';
 import Vuex from 'vuex';
-import { calculateSwimlanesBufferSize } from 'ee/boards/boards_util';
+import * as BoardUtils from 'ee/boards/boards_util';
 import EpicLane from 'ee/boards/components/epic_lane.vue';
 import EpicsSwimlanes from 'ee/boards/components/epics_swimlanes.vue';
 import IssueLaneList from 'ee/boards/components/issues_lane_list.vue';
@@ -20,6 +20,7 @@ jest.mock('ee/boards/boards_util');
 
 describe('EpicsSwimlanes', () => {
   let wrapper;
+  const bufferSize = 100;
 
   const findDraggable = () => wrapper.findComponent(Draggable);
   const findLoadMoreEpicsButton = () => wrapper.findByTestId('load-more-epics');
@@ -69,7 +70,6 @@ describe('EpicsSwimlanes', () => {
 
   const createComponent = ({
     canAdminList = false,
-    swimlanesBufferedRendering = false,
     epicLanesFetchInProgress = false,
     listItemsFetchInProgress = false,
     hasMoreEpics = false,
@@ -84,13 +84,14 @@ describe('EpicsSwimlanes', () => {
       shallowMount(EpicsSwimlanes, {
         propsData: { ...defaultProps, canAdminList },
         store,
-        provide: {
-          glFeatures: { swimlanesBufferedRendering },
-        },
       }),
     );
   };
 
+  beforeEach(() => {
+    jest.spyOn(BoardUtils, 'calculateSwimlanesBufferSize').mockReturnValue(bufferSize);
+  });
+
   afterEach(() => {
     wrapper.destroy();
   });
@@ -133,14 +134,29 @@ describe('EpicsSwimlanes', () => {
       expect(wrapper.findAllComponents(BoardListHeader)).toHaveLength(4);
     });
 
-    it('displays EpicLane components for epic', () => {
-      expect(wrapper.findAllComponents(EpicLane)).toHaveLength(5);
-    });
-
     it('does not display IssueLaneList component by default', () => {
       expect(wrapper.findComponent(IssueLaneList).exists()).toBe(false);
     });
 
+    it('renders virtual-list', () => {
+      const virtualList = wrapper.findComponent(VirtualList);
+      const scrollableContainer = wrapper.find({ ref: 'scrollableContainer' }).element;
+
+      expect(BoardUtils.calculateSwimlanesBufferSize).toHaveBeenCalledWith(
+        wrapper.element.offsetTop,
+      );
+      expect(virtualList.props()).toMatchObject({
+        remain: bufferSize,
+        bench: bufferSize,
+        item: EpicLane,
+        size: EPIC_LANE_BASE_HEIGHT,
+        itemcount: mockEpics.length,
+        itemprops: expect.any(Function),
+      });
+
+      expect(virtualList.props().scrollelement).toBe(scrollableContainer);
+    });
+
     it('does not display load more epics button if there are no more epics', () => {
       expect(findLoadMoreEpicsButton().exists()).toBe(false);
     });
@@ -204,30 +220,4 @@ describe('EpicsSwimlanes', () => {
       },
     );
   });
-
-  describe('when swimlanesBufferedRendering is true', () => {
-    const bufferSize = 100;
-
-    beforeEach(() => {
-      calculateSwimlanesBufferSize.mockReturnValueOnce(bufferSize);
-      createComponent({ swimlanesBufferedRendering: true });
-    });
-
-    it('renders virtual-list', () => {
-      const virtualList = wrapper.find(VirtualList);
-      const scrollableContainer = wrapper.find({ ref: 'scrollableContainer' }).element;
-
-      expect(calculateSwimlanesBufferSize).toHaveBeenCalledWith(wrapper.element.offsetTop);
-      expect(virtualList.props()).toMatchObject({
-        remain: bufferSize,
-        bench: bufferSize,
-        item: EpicLane,
-        size: EPIC_LANE_BASE_HEIGHT,
-        itemcount: mockEpics.length,
-        itemprops: expect.any(Function),
-      });
-
-      expect(virtualList.props().scrollelement).toBe(scrollableContainer);
-    });
-  });
 });

spec/controllers/groups/boards_controller_spec.rb

@@ -16,15 +16,6 @@ RSpec.describe Groups::BoardsController do
       expect { list_boards }.to change(group.boards, :count).by(1)
     end
 
-    it 'pushes swimlanes_buffered_rendering feature flag' do
-      allow(controller).to receive(:push_frontend_feature_flag).and_call_original
-
-      expect(controller).to receive(:push_frontend_feature_flag)
-        .with(:swimlanes_buffered_rendering, group, default_enabled: :yaml)
-
-      list_boards
-    end
-
     context 'when format is HTML' do
       it 'renders template' do
         list_boards
@@ -107,15 +98,6 @@ RSpec.describe Groups::BoardsController do
   describe 'GET show' do
     let!(:board) { create(:board, group: group) }
 
-    it 'pushes swimlanes_buffered_rendering feature flag' do
-      allow(controller).to receive(:push_frontend_feature_flag).and_call_original
-
-      expect(controller).to receive(:push_frontend_feature_flag)
-        .with(:swimlanes_buffered_rendering, group, default_enabled: :yaml)
-
-      read_board board: board
-    end
-
     context 'when format is HTML' do
       it 'renders template' do
         expect { read_board board: board }.to change(BoardGroupRecentVisit, :count).by(1)

spec/controllers/projects/boards_controller_spec.rb

@@ -22,15 +22,6 @@ RSpec.describe Projects::BoardsController do
       expect(assigns(:boards_endpoint)).to eq project_boards_path(project)
     end
 
-    it 'pushes swimlanes_buffered_rendering feature flag' do
-      allow(controller).to receive(:push_frontend_feature_flag).and_call_original
-
-      expect(controller).to receive(:push_frontend_feature_flag)
-        .with(:swimlanes_buffered_rendering, project, default_enabled: :yaml)
-
-      list_boards
-    end
-
     context 'when format is HTML' do
       it 'renders template' do
         list_boards
@@ -125,15 +116,6 @@ RSpec.describe Projects::BoardsController do
   describe 'GET show' do
     let!(:board) { create(:board, project: project) }
 
-    it 'pushes swimlanes_buffered_rendering feature flag' do
-      allow(controller).to receive(:push_frontend_feature_flag).and_call_original
-
-      expect(controller).to receive(:push_frontend_feature_flag)
-        .with(:swimlanes_buffered_rendering, project, default_enabled: :yaml)
-
-      read_board board: board
-    end
-
     it 'sets boards_endpoint instance variable to a boards path' do
       read_board board: board