diff --git a/.gitlab/ci/rules.gitlab-ci.yml b/.gitlab/ci/rules.gitlab-ci.yml
index b9cf5a7d5bd..0817afe6cda 100644
--- a/.gitlab/ci/rules.gitlab-ci.yml
+++ b/.gitlab/ci/rules.gitlab-ci.yml
@@ -189,7 +189,7 @@
   - "config.ru"
   # List explicitly all the app/ dirs that are backend (i.e. all except app/assets).
   - "{,ee/,jh/}{app/channels,app/controllers,app/finders,app/graphql,app/helpers,app/mailers,app/models,app/policies,app/presenters,app/serializers,app/services,app/uploaders,app/validators,app/views,app/workers}/**/*"
-  - "{,ee/,jh/}{bin,cable,config,db,lib}/**/*"
+  - "{,ee/,jh/}{bin,cable,config,db,generator_templates,lib}/**/*"
   - "{,ee/,jh/}spec/**/*.rb"
   # CI changes
   - ".gitlab-ci.yml"
@@ -239,7 +239,7 @@
   - "Rakefile"
   - "tests.yml"
   - "config.ru"
-  - "{,ee/,jh/}{app,bin,config,db,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
+  - "{,ee/,jh/}{app,bin,config,db,generator_templates,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
   - "doc/api/graphql/reference/*"  # Files in this folder are auto-generated
   - "data/whats_new/*.yml"
 
@@ -264,7 +264,7 @@
   - "Rakefile"
   - "tests.yml"
   - "config.ru"
-  - "{,ee/,jh/}{app,bin,config,db,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
+  - "{,ee/,jh/}{app,bin,config,db,generator_templates,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
   - "doc/api/graphql/reference/*"  # Files in this folder are auto-generated
   - "data/whats_new/*.yml"
   # Backstage changes
@@ -292,7 +292,7 @@
   - "Rakefile"
   - "tests.yml"
   - "config.ru"
-  - "{,ee/,jh/}{app,bin,config,db,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
+  - "{,ee/,jh/}{app,bin,config,db,generator_templates,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
   - "doc/api/graphql/reference/*"  # Files in this folder are auto-generated
   - "data/whats_new/*.yml"
   # QA changes
@@ -316,7 +316,7 @@
   - "Rakefile"
   - "tests.yml"
   - "config.ru"
-  - "{,ee/,jh/}{app,bin,config,db,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
+  - "{,ee/,jh/}{app,bin,config,db,generator_templates,haml_lint,lib,locale,public,scripts,symbol,vendor}/**/*"
   - "doc/api/graphql/reference/*"  # Files in this folder are auto-generated
   - "data/whats_new/*.yml"
   # Backstage changes
diff --git a/GITALY_SERVER_VERSION b/GITALY_SERVER_VERSION
index 3116f541e87..7cd6346ac01 100644
--- a/GITALY_SERVER_VERSION
+++ b/GITALY_SERVER_VERSION
@@ -1 +1 @@
-9cde7b7d1ecc68f5ca3b68df5ad32e6b0bc9d661
+ebabe4399c781ea1f4a1a43774b14489446f1f68
diff --git a/app/assets/javascripts/boards/components/board_content_sidebar.vue b/app/assets/javascripts/boards/components/board_content_sidebar.vue
index f927b03a22b..e014b82d362 100644
--- a/app/assets/javascripts/boards/components/board_content_sidebar.vue
+++ b/app/assets/javascripts/boards/components/board_content_sidebar.vue
@@ -11,6 +11,7 @@ import SidebarAssigneesWidget from '~/sidebar/components/assignees/sidebar_assig
 import SidebarConfidentialityWidget from '~/sidebar/components/confidential/sidebar_confidentiality_widget.vue';
 import SidebarDateWidget from '~/sidebar/components/date/sidebar_date_widget.vue';
 import SidebarSubscriptionsWidget from '~/sidebar/components/subscriptions/sidebar_subscriptions_widget.vue';
+import SidebarTodoWidget from '~/sidebar/components/todo_toggle/sidebar_todo_widget.vue';
 import glFeatureFlagMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 
 export default {
@@ -24,6 +25,7 @@ export default {
     BoardSidebarLabelsSelect,
     SidebarSubscriptionsWidget,
     SidebarDropdownWidget,
+    SidebarTodoWidget,
     MountingPortal,
     SidebarWeightWidget: () =>
       import('ee_component/sidebar/components/weight/sidebar_weight_widget.vue'),
@@ -90,6 +92,15 @@ export default {
       <template #title>
         <h2 class="gl-my-0 gl-font-size-h2 gl-line-height-24">{{ __('Issue details') }}</h2>
       </template>
+      <template #header>
+        <sidebar-todo-widget
+          class="gl-mt-3"
+          :issuable-id="activeBoardItem.fullId"
+          :issuable-iid="activeBoardItem.iid"
+          :full-path="fullPath"
+          :issuable-type="issuableType"
+        />
+      </template>
       <template #default>
         <board-sidebar-title />
         <sidebar-assignees-widget
diff --git a/app/assets/javascripts/design_management/components/design_todo_button.vue b/app/assets/javascripts/design_management/components/design_todo_button.vue
index c614fee17d1..013dd1d89f3 100644
--- a/app/assets/javascripts/design_management/components/design_todo_button.vue
+++ b/app/assets/javascripts/design_management/components/design_todo_button.vue
@@ -1,6 +1,6 @@
 <script>
 import todoMarkDoneMutation from '~/graphql_shared/mutations/todo_mark_done.mutation.graphql';
-import TodoButton from '~/vue_shared/components/sidebar/todo_button.vue';
+import TodoButton from '~/vue_shared/components/sidebar/todo_toggle/todo_button.vue';
 import createDesignTodoMutation from '../graphql/mutations/create_design_todo.mutation.graphql';
 import getDesignQuery from '../graphql/queries/get_design.query.graphql';
 import allVersionsMixin from '../mixins/all_versions';
diff --git a/app/assets/javascripts/right_sidebar.js b/app/assets/javascripts/right_sidebar.js
index 24041a60e3d..36f5e6f4ce1 100644
--- a/app/assets/javascripts/right_sidebar.js
+++ b/app/assets/javascripts/right_sidebar.js
@@ -2,7 +2,7 @@
 
 import $ from 'jquery';
 import Cookies from 'js-cookie';
-import { fixTitle, hide } from '~/tooltips';
+import { hide } from '~/tooltips';
 import createFlash from './flash';
 import axios from './lib/utils/axios_utils';
 import { sprintf, s__, __ } from './locale';
@@ -107,36 +107,6 @@ Sidebar.prototype.toggleTodo = function (e) {
     );
 };
 
-Sidebar.prototype.todoUpdateDone = function (data) {
-  const deletePath = data.delete_path ? data.delete_path : null;
-  const attrPrefix = deletePath ? 'mark' : 'todo';
-  const $todoBtns = $('.js-issuable-todo');
-
-  $(document).trigger('todo:toggle', data.count);
-
-  $todoBtns.each((i, el) => {
-    const $el = $(el);
-    const $elText = $el.find('.js-issuable-todo-inner');
-
-    $el
-      .removeClass('is-loading')
-      .enable()
-      .attr('aria-label', $el.data(`${attrPrefix}Text`))
-      .attr('title', $el.data(`${attrPrefix}Text`))
-      .data('deletePath', deletePath);
-
-    if ($el.hasClass('has-tooltip')) {
-      fixTitle(el);
-    }
-
-    if (typeof $el.data('isCollapsed') !== 'undefined') {
-      $elText.html($el.data(`${attrPrefix}Icon`));
-    } else {
-      $elText.text($el.data(`${attrPrefix}Text`));
-    }
-  });
-};
-
 Sidebar.prototype.sidebarCollapseClicked = function (e) {
   if ($(e.currentTarget).hasClass('dont-change-state')) {
     return;
diff --git a/app/assets/javascripts/sidebar/components/todo_toggle/sidebar_todo_widget.vue b/app/assets/javascripts/sidebar/components/todo_toggle/sidebar_todo_widget.vue
index 18eab0126a4..a9c4203af22 100644
--- a/app/assets/javascripts/sidebar/components/todo_toggle/sidebar_todo_widget.vue
+++ b/app/assets/javascripts/sidebar/components/todo_toggle/sidebar_todo_widget.vue
@@ -1,18 +1,26 @@
 <script>
-import { GlTooltipDirective } from '@gitlab/ui';
+import { GlButton, GlIcon, GlTooltipDirective } from '@gitlab/ui';
 import { produce } from 'immer';
 import createFlash from '~/flash';
 import { __, sprintf } from '~/locale';
 import { todoQueries, TodoMutationTypes, todoMutations } from '~/sidebar/constants';
-import TodoButton from '~/vue_shared/components/sidebar/todo_button.vue';
+import { todoLabel } from '~/vue_shared/components/sidebar/todo_toggle//utils';
+import TodoButton from '~/vue_shared/components/sidebar/todo_toggle/todo_button.vue';
 
 export default {
   components: {
+    GlButton,
+    GlIcon,
     TodoButton,
   },
   directives: {
     GlTooltip: GlTooltipDirective,
   },
+  inject: {
+    isClassicSidebar: {
+      default: false,
+    },
+  },
   props: {
     issuableId: {
       type: String,
@@ -86,6 +94,12 @@ export default {
       }
       return TodoMutationTypes.Create;
     },
+    collapsedButtonIcon() {
+      return this.hasTodo ? 'todo-done' : 'todo-add';
+    },
+    tootltipTitle() {
+      return todoLabel(this.hasTodo);
+    },
   },
   methods: {
     toggleTodo() {
@@ -158,7 +172,24 @@ export default {
       :is-todo="hasTodo"
       :loading="isLoading"
       size="small"
+      class="hide-collapsed"
       @click.stop.prevent="toggleTodo"
     />
+    <gl-button
+      v-if="isClassicSidebar"
+      category="tertiary"
+      type="reset"
+      class="sidebar-collapsed-icon sidebar-collapsed-container gl-rounded-0! gl-shadow-none!"
+      @click.stop.prevent="toggleTodo"
+    >
+      <gl-icon
+        v-gl-tooltip.left.viewport
+        :title="tootltipTitle"
+        :size="16"
+        :class="{ 'todo-undone': hasTodo }"
+        :name="collapsedButtonIcon"
+        :aria-label="collapsedButtonIcon"
+      />
+    </gl-button>
   </div>
 </template>
diff --git a/app/assets/javascripts/sidebar/constants.js b/app/assets/javascripts/sidebar/constants.js
index 20ef783f093..08ee4379c0c 100644
--- a/app/assets/javascripts/sidebar/constants.js
+++ b/app/assets/javascripts/sidebar/constants.js
@@ -13,10 +13,12 @@ import issueDueDateQuery from '~/sidebar/queries/issue_due_date.query.graphql';
 import issueReferenceQuery from '~/sidebar/queries/issue_reference.query.graphql';
 import issueSubscribedQuery from '~/sidebar/queries/issue_subscribed.query.graphql';
 import issueTimeTrackingQuery from '~/sidebar/queries/issue_time_tracking.query.graphql';
+import issueTodoQuery from '~/sidebar/queries/issue_todo.query.graphql';
 import mergeRequestMilestone from '~/sidebar/queries/merge_request_milestone.query.graphql';
 import mergeRequestReferenceQuery from '~/sidebar/queries/merge_request_reference.query.graphql';
 import mergeRequestSubscribed from '~/sidebar/queries/merge_request_subscribed.query.graphql';
 import mergeRequestTimeTrackingQuery from '~/sidebar/queries/merge_request_time_tracking.query.graphql';
+import mergeRequestTodoQuery from '~/sidebar/queries/merge_request_todo.query.graphql';
 import todoCreateMutation from '~/sidebar/queries/todo_create.mutation.graphql';
 import todoMarkDoneMutation from '~/sidebar/queries/todo_mark_done.mutation.graphql';
 import updateEpicConfidentialMutation from '~/sidebar/queries/update_epic_confidential.mutation.graphql';
@@ -216,6 +218,12 @@ export const todoQueries = {
   [IssuableType.Epic]: {
     query: epicTodoQuery,
   },
+  [IssuableType.Issue]: {
+    query: issueTodoQuery,
+  },
+  [IssuableType.MergeRequest]: {
+    query: mergeRequestTodoQuery,
+  },
 };
 
 export const TodoMutationTypes = {
diff --git a/app/assets/javascripts/sidebar/mount_sidebar.js b/app/assets/javascripts/sidebar/mount_sidebar.js
index e4227a1f42c..dd1b439c482 100644
--- a/app/assets/javascripts/sidebar/mount_sidebar.js
+++ b/app/assets/javascripts/sidebar/mount_sidebar.js
@@ -2,6 +2,8 @@ import $ from 'jquery';
 import Vue from 'vue';
 import VueApollo from 'vue-apollo';
 import createFlash from '~/flash';
+import { TYPE_ISSUE, TYPE_MERGE_REQUEST } from '~/graphql_shared/constants';
+import { convertToGraphQLId } from '~/graphql_shared/utils';
 import initInviteMembersModal from '~/invite_members/init_invite_members_modal';
 import initInviteMembersTrigger from '~/invite_members/init_invite_members_trigger';
 import { IssuableType } from '~/issue_show/constants';
@@ -19,6 +21,7 @@ import SidebarDueDateWidget from '~/sidebar/components/date/sidebar_date_widget.
 import SidebarParticipantsWidget from '~/sidebar/components/participants/sidebar_participants_widget.vue';
 import SidebarReferenceWidget from '~/sidebar/components/reference/sidebar_reference_widget.vue';
 import SidebarDropdownWidget from '~/sidebar/components/sidebar_dropdown_widget.vue';
+import SidebarTodoWidget from '~/sidebar/components/todo_toggle/sidebar_todo_widget.vue';
 import { apolloProvider } from '~/sidebar/graphql';
 import trackShowInviteMemberLink from '~/sidebar/track_invite_members';
 import Translate from '../vue_shared/translate';
@@ -40,6 +43,40 @@ function getSidebarOptions(sidebarOptEl = document.querySelector('.js-sidebar-op
   return JSON.parse(sidebarOptEl.innerHTML);
 }
 
+function mountSidebarToDoWidget() {
+  const el = document.querySelector('.js-issuable-todo');
+
+  if (!el) {
+    return false;
+  }
+
+  const { projectPath, iid, id } = el.dataset;
+
+  return new Vue({
+    el,
+    apolloProvider,
+    components: {
+      SidebarTodoWidget,
+    },
+    provide: {
+      isClassicSidebar: true,
+    },
+    render: (createElement) =>
+      createElement('sidebar-todo-widget', {
+        props: {
+          fullPath: projectPath,
+          issuableId:
+            isInIssuePage() || isInDesignPage()
+              ? convertToGraphQLId(TYPE_ISSUE, id)
+              : convertToGraphQLId(TYPE_MERGE_REQUEST, id),
+          issuableIid: iid,
+          issuableType:
+            isInIssuePage() || isInDesignPage() ? IssuableType.Issue : IssuableType.MergeRequest,
+        },
+      }),
+  });
+}
+
 function getSidebarAssigneeAvailabilityData() {
   const sidebarAssigneeEl = document.querySelectorAll('.js-sidebar-assignee-data input');
   return Array.from(sidebarAssigneeEl)
@@ -497,6 +534,7 @@ export function mountSidebar(mediator) {
   initInviteMembersModal();
   initInviteMembersTrigger();
 
+  mountSidebarToDoWidget();
   if (isAssigneesWidgetShown) {
     mountAssigneesComponent();
   } else {
diff --git a/app/assets/javascripts/sidebar/queries/issue_todo.query.graphql b/app/assets/javascripts/sidebar/queries/issue_todo.query.graphql
new file mode 100644
index 00000000000..783d36352fe
--- /dev/null
+++ b/app/assets/javascripts/sidebar/queries/issue_todo.query.graphql
@@ -0,0 +1,14 @@
+query issueTodos($fullPath: ID!, $iid: String!) {
+  workspace: project(fullPath: $fullPath) {
+    __typename
+    issuable: issue(iid: $iid) {
+      __typename
+      id
+      currentUserTodos(state: pending) {
+        nodes {
+          id
+        }
+      }
+    }
+  }
+}
diff --git a/app/assets/javascripts/sidebar/queries/merge_request_todo.query.graphql b/app/assets/javascripts/sidebar/queries/merge_request_todo.query.graphql
new file mode 100644
index 00000000000..93a1c9ea925
--- /dev/null
+++ b/app/assets/javascripts/sidebar/queries/merge_request_todo.query.graphql
@@ -0,0 +1,14 @@
+query mergeRequestTodos($fullPath: ID!, $iid: String!) {
+  workspace: project(fullPath: $fullPath) {
+    __typename
+    issuable: mergeRequest(iid: $iid) {
+      __typename
+      id
+      currentUserTodos(state: pending) {
+        nodes {
+          id
+        }
+      }
+    }
+  }
+}
diff --git a/app/assets/javascripts/vue_shared/components/sidebar/todo_button.stories.js b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.stories.js
similarity index 90%
rename from app/assets/javascripts/vue_shared/components/sidebar/todo_button.stories.js
rename to app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.stories.js
index db4d8724a0d..d2afc02233e 100644
--- a/app/assets/javascripts/vue_shared/components/sidebar/todo_button.stories.js
+++ b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.stories.js
@@ -4,7 +4,7 @@ import TodoButton from './todo_button.vue';
 
 export default {
   component: TodoButton,
-  title: 'vue_shared/components/todo_button',
+  title: 'vue_shared/components/todo_toggle/todo_button',
 };
 
 const Template = (args, { argTypes }) => ({
diff --git a/app/assets/javascripts/vue_shared/components/sidebar/todo_button.vue b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.vue
similarity index 92%
rename from app/assets/javascripts/vue_shared/components/sidebar/todo_button.vue
rename to app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.vue
index a3517183515..e6229cf0a93 100644
--- a/app/assets/javascripts/vue_shared/components/sidebar/todo_button.vue
+++ b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.vue
@@ -1,6 +1,6 @@
 <script>
 import { GlButton } from '@gitlab/ui';
-import { __ } from '~/locale';
+import { todoLabel } from './utils';
 
 export default {
   components: {
@@ -15,7 +15,7 @@ export default {
   },
   computed: {
     buttonLabel() {
-      return this.isTodo ? __('Mark as done') : __('Add a to do');
+      return todoLabel(this.isTodo);
     },
   },
   methods: {
diff --git a/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/utils.js b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/utils.js
new file mode 100644
index 00000000000..59e72a2ffe3
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/utils.js
@@ -0,0 +1,5 @@
+import { __ } from '~/locale';
+
+export const todoLabel = (hasTodo) => {
+  return hasTodo ? __('Mark as done') : __('Add a to do');
+};
diff --git a/app/assets/stylesheets/pages/issuable.scss b/app/assets/stylesheets/pages/issuable.scss
index 1bc6dfbd84a..ee97e8af296 100644
--- a/app/assets/stylesheets/pages/issuable.scss
+++ b/app/assets/stylesheets/pages/issuable.scss
@@ -175,7 +175,8 @@
     }
   }
 
-  .block {
+  .block,
+  .issuable-sidebar-header {
     @include clearfix;
     padding: $gl-padding 0;
     border-bottom: 1px solid $border-gray-normal;
@@ -184,11 +185,6 @@
     width: $gutter-inner-width;
     // --
 
-    &.issuable-sidebar-header {
-      padding-top: 0;
-      padding-bottom: 10px;
-    }
-
     &:last-child {
       border: 0;
     }
@@ -273,10 +269,6 @@
       padding: 0 20px;
     }
 
-    .issuable-sidebar-header {
-      padding-top: 10px;
-    }
-
     &:not(.boards-sidebar):not([data-signed-in]):not([data-always-show-toggle]) {
       .issuable-sidebar-header {
         display: none;
@@ -302,7 +294,6 @@
     }
 
     .gutter-toggle {
-      margin-top: 7px;
       border-left: 1px solid $border-gray-normal;
       text-align: center;
     }
@@ -331,20 +322,21 @@
     width: $gutter-collapsed-width;
     padding: 0;
 
-    .block {
+    .block,
+    .issuable-sidebar-header {
       width: $gutter-collapsed-width - 2px;
       padding: 0;
       border-bottom: 0;
       overflow: hidden;
+    }
 
+    .block,
+    .gutter-toggle,
+    .sidebar-collapsed-container {
       &.with-sub-blocks .sub-block:hover,
       &:not(.with-sub-blocks):hover {
         background-color: $gray-100;
       }
-
-      &.issuable-sidebar-header {
-        padding-top: 0;
-      }
     }
 
     .participants {
diff --git a/app/controllers/projects/merge_requests/diffs_controller.rb b/app/controllers/projects/merge_requests/diffs_controller.rb
index d570fc06d93..88423bec915 100644
--- a/app/controllers/projects/merge_requests/diffs_controller.rb
+++ b/app/controllers/projects/merge_requests/diffs_controller.rb
@@ -3,6 +3,7 @@
 class Projects::MergeRequests::DiffsController < Projects::MergeRequests::ApplicationController
   include DiffHelper
   include RendersNotes
+  include Gitlab::Cache::Helpers
 
   before_action :commit
   before_action :define_diff_vars
@@ -40,7 +41,16 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
       pagination_data: diffs.pagination_data
     }
 
-    render json: PaginatedDiffSerializer.new(current_user: current_user).represent(diffs, options)
+    if diff_options_hash[:paths].blank? && Feature.enabled?(:diffs_batch_render_cached, project, default_enabled: :yaml)
+      render_cached(
+        diffs,
+        with: PaginatedDiffSerializer.new(current_user: current_user),
+        cache_context: -> (_) { [diff_view, params[:w], params[:expanded], params[:per_page], params[:page]] },
+        **options
+      )
+    else
+      render json: PaginatedDiffSerializer.new(current_user: current_user).represent(diffs, options)
+    end
   end
 
   def diffs_metadata
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 2e15b3f22c2..1304bcb1c7e 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -285,7 +285,7 @@ module ApplicationHelper
   def page_class
     class_names = []
     class_names << 'issue-boards-page gl-overflow-auto' if current_controller?(:boards)
-    class_names << 'epic-boards-page' if current_controller?(:epic_boards)
+    class_names << 'epic-boards-page gl-overflow-auto' if current_controller?(:epic_boards)
     class_names << 'environment-logs-page' if current_controller?(:logs)
     class_names << 'with-performance-bar' if performance_bar_enabled?
     class_names << system_message_class
diff --git a/app/models/concerns/analytics/cycle_analytics/stage.rb b/app/models/concerns/analytics/cycle_analytics/stage.rb
index 90d48aa81d0..2a0274f5706 100644
--- a/app/models/concerns/analytics/cycle_analytics/stage.rb
+++ b/app/models/concerns/analytics/cycle_analytics/stage.rb
@@ -50,6 +50,10 @@ module Analytics
         end
       end
 
+      def events_hash_code
+        Digest::SHA256.hexdigest("#{start_event.hash_code}-#{end_event.hash_code}")
+      end
+
       def start_event_label_based?
         start_event_identifier && start_event.label_based?
       end
diff --git a/app/models/diff_discussion.rb b/app/models/diff_discussion.rb
index 6806008d676..642e93f7912 100644
--- a/app/models/diff_discussion.rb
+++ b/app/models/diff_discussion.rb
@@ -42,6 +42,13 @@ class DiffDiscussion < Discussion
     )
   end
 
+  def cache_key
+    [
+      super,
+      Digest::SHA1.hexdigest(position.to_json)
+    ].join(':')
+  end
+
   private
 
   def get_params
diff --git a/app/services/merge_requests/rebase_service.rb b/app/services/merge_requests/rebase_service.rb
index ae8398e2335..9423194c01d 100644
--- a/app/services/merge_requests/rebase_service.rb
+++ b/app/services/merge_requests/rebase_service.rb
@@ -18,12 +18,6 @@ module MergeRequests
     end
 
     def rebase
-      # Ensure Gitaly isn't already running a rebase
-      if source_project.repository.rebase_in_progress?(merge_request.id)
-        log_error(exception: nil, message: 'Rebase task canceled: Another rebase is already in progress', save_message_on_model: true)
-        return false
-      end
-
       repository.rebase(current_user, merge_request, skip_ci: @skip_ci)
 
       true
diff --git a/app/views/shared/issuable/_sidebar.html.haml b/app/views/shared/issuable/_sidebar.html.haml
index 82f03421799..c76aa176696 100644
--- a/app/views/shared/issuable/_sidebar.html.haml
+++ b/app/views/shared/issuable/_sidebar.html.haml
@@ -10,19 +10,13 @@
 
 %aside.right-sidebar.js-right-sidebar.js-issuable-sidebar{ data: { signed: { in: signed_in }, issuable_type: issuable_type }, class: sidebar_gutter_collapsed_class, 'aria-live' => 'polite', 'aria-label': issuable_type }
   .issuable-sidebar
-    .block.issuable-sidebar-header
-      - if signed_in
-        %span.issuable-header-text.hide-collapsed.float-left
-          = _('To Do')
+    .issuable-sidebar-header.gl-py-3
       %a.gutter-toggle.float-right.js-sidebar-toggle.has-tooltip{ role: "button", href: "#", "aria-label" => _('Toggle sidebar'), title: sidebar_gutter_tooltip_text, data: { container: 'body', placement: 'left', boundary: 'viewport' } }
         = sidebar_gutter_toggle_icon
       - if signed_in
-        = render "shared/issuable/sidebar_todo", issuable_sidebar: issuable_sidebar
+        .js-issuable-todo{ data: { project_path: issuable_sidebar[:project_full_path], iid: issuable_sidebar[:iid], id: issuable_sidebar[:id] } }
 
     = form_for issuable_type, url: issuable_sidebar[:issuable_json_path], remote: true, html: { class: 'issuable-context-form inline-update js-issuable-update' } do |f|
-      - if signed_in
-        .block.todo.hide-expanded
-          = render "shared/issuable/sidebar_todo", issuable_sidebar: issuable_sidebar, is_collapsed: true
       .block.assignee.qa-assignee-block
         = render "shared/issuable/sidebar_assignees", issuable_sidebar: issuable_sidebar, assignees: assignees, signed_in: signed_in
 
diff --git a/app/views/shared/issuable/_sidebar_todo.html.haml b/app/views/shared/issuable/_sidebar_todo.html.haml
deleted file mode 100644
index a867421298b..00000000000
--- a/app/views/shared/issuable/_sidebar_todo.html.haml
+++ /dev/null
@@ -1,15 +0,0 @@
-- is_collapsed = local_assigns.fetch(:is_collapsed, false)
-- has_todo = !!issuable_sidebar.dig(:current_user, :todo, :id)
-
-- todo_button_data = issuable_todo_button_data(issuable_sidebar, is_collapsed)
-- button_title = has_todo ? todo_button_data[:mark_text] : todo_button_data[:todo_text]
-- button_icon = has_todo ? todo_button_data[:mark_icon] : todo_button_data[:todo_icon]
-
-%button.issuable-todo-btn.js-issuable-todo{ type: 'button',
-  class: (is_collapsed ? 'btn-blank sidebar-collapsed-icon dont-change-state has-tooltip' : 'gl-button btn btn-default issuable-header-btn float-right'),
-  title: button_title,
-  'aria-label' => button_title,
-  data: todo_button_data }
-  %span.issuable-todo-inner.js-issuable-todo-inner<
-    = is_collapsed ? button_icon : button_title
-  = loading_icon(css_class: is_collapsed ? '' : 'gl-ml-3')
diff --git a/config/feature_flags/development/diffs_batch_render_cached.yml b/config/feature_flags/development/diffs_batch_render_cached.yml
new file mode 100644
index 00000000000..ee2deaa4072
--- /dev/null
+++ b/config/feature_flags/development/diffs_batch_render_cached.yml
@@ -0,0 +1,8 @@
+---
+name: diffs_batch_render_cached
+introduced_by_url: https://gitlab.com/gitlab-org/security/gitlab/-/merge_requests/1509
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/334762
+milestone: '14.1'
+type: development
+group: group::code review
+default_enabled: false
diff --git a/doc/ci/triggers/index.md b/doc/ci/triggers/index.md
index 15a2a8a3c3f..383887bd389 100644
--- a/doc/ci/triggers/index.md
+++ b/doc/ci/triggers/index.md
@@ -114,7 +114,7 @@ The action is irreversible.
 
 ## Triggering a pipeline
 
-To trigger a job you need to send a `POST` request to the GitLab API endpoint:
+To trigger a pipeline you need to send a `POST` request to the GitLab API endpoint:
 
 ```plaintext
 POST /projects/:id/trigger/pipeline
@@ -126,7 +126,7 @@ branches or tags. The `:id` of a project can be found by
 [querying the API](../../api/projects.md) or by visiting the **CI/CD**
 settings page which provides self-explanatory examples.
 
-When a rerun of a pipeline is triggered, jobs are marked as triggered `by API` in
+When a rerun of a pipeline is triggered, jobs are labeled as `triggered` in
 **CI/CD > Jobs**.
 
 You can see which trigger caused a job to run by visiting the single job page.
diff --git a/doc/ci/yaml/index.md b/doc/ci/yaml/index.md
index 26974eb4abd..d1728ba2949 100644
--- a/doc/ci/yaml/index.md
+++ b/doc/ci/yaml/index.md
@@ -26,39 +26,40 @@ A job is defined as a list of keywords that define the job's behavior.
 
 The keywords available for jobs are:
 
-| Keyword                             | Description |
-| :-----------------------------------|:------------|
-| [`after_script`](#after_script)     | Override a set of commands that are executed after job. |
-| [`allow_failure`](#allow_failure)   | Allow job to fail. A failed job does not cause the pipeline to fail. |
-| [`artifacts`](#artifacts)           | List of files and directories to attach to a job on success. |
-| [`before_script`](#before_script)   | Override a set of commands that are executed before job. |
-| [`cache`](#cache)                   | List of files that should be cached between subsequent runs. |
-| [`coverage`](#coverage)             | Code coverage settings for a given job. |
-| [`dependencies`](#dependencies)     | Restrict which artifacts are passed to a specific job by providing a list of jobs to fetch artifacts from. |
-| [`environment`](#environment)       | Name of an environment to which the job deploys. |
-| [`except`](#only--except)           | Control when jobs are not created. |
-| [`extends`](#extends)               | Configuration entries that this job inherits from. |
-| [`image`](#image)                   | Use Docker images. |
-| [`include`](#include)               | Include external YAML files. |
-| [`inherit`](#inherit)               | Select which global defaults all jobs inherit. |
-| [`interruptible`](#interruptible)   | Defines if a job can be canceled when made redundant by a newer run. |
-| [`needs`](#needs)                   | Execute jobs earlier than the stage ordering. |
-| [`only`](#only--except)             | Control when jobs are created. |
-| [`pages`](#pages)                   | Upload the result of a job to use with GitLab Pages. |
-| [`parallel`](#parallel)             | How many instances of a job should be run in parallel. |
-| [`release`](#release)               | Instructs the runner to generate a [release](../../user/project/releases/index.md) object. |
-| [`resource_group`](#resource_group) | Limit job concurrency. |
-| [`retry`](#retry)                   | When and how many times a job can be auto-retried in case of a failure. |
-| [`rules`](#rules)                   | List of conditions to evaluate and determine selected attributes of a job, and whether or not it's created. |
-| [`script`](#script)                 | Shell script that is executed by a runner. |
-| [`secrets`](#secrets)               | The CI/CD secrets the job needs. |
-| [`services`](#services)             | Use Docker services images. |
-| [`stage`](#stage)                   | Defines a job stage. |
-| [`tags`](#tags)                     | List of tags that are used to select a runner. |
-| [`timeout`](#timeout)               | Define a custom job-level timeout that takes precedence over the project-wide setting. |
-| [`trigger`](#trigger)               | Defines a downstream pipeline trigger. |
-| [`variables`](#variables)           | Define job variables on a job level. |
-| [`when`](#when)                     | When to run job. |
+| Keyword                                     | Description |
+| :-------------------------------------------|:------------|
+| [`after_script`](#after_script)             | Override a set of commands that are executed after job. |
+| [`allow_failure`](#allow_failure)           | Allow job to fail. A failed job does not cause the pipeline to fail. |
+| [`artifacts`](#artifacts)                   | List of files and directories to attach to a job on success. |
+| [`before_script`](#before_script)           | Override a set of commands that are executed before job. |
+| [`cache`](#cache)                           | List of files that should be cached between subsequent runs. |
+| [`coverage`](#coverage)                     | Code coverage settings for a given job. |
+| [`dast_configuration`](#dast_configuration) | Use configuration from DAST profiles on a job level. |
+| [`dependencies`](#dependencies)             | Restrict which artifacts are passed to a specific job by providing a list of jobs to fetch artifacts from. |
+| [`environment`](#environment)               | Name of an environment to which the job deploys. |
+| [`except`](#only--except)                   | Control when jobs are not created. |
+| [`extends`](#extends)                       | Configuration entries that this job inherits from. |
+| [`image`](#image)                           | Use Docker images. |
+| [`include`](#include)                       | Include external YAML files. |
+| [`inherit`](#inherit)                       | Select which global defaults all jobs inherit. |
+| [`interruptible`](#interruptible)           | Defines if a job can be canceled when made redundant by a newer run. |
+| [`needs`](#needs)                           | Execute jobs earlier than the stage ordering. |
+| [`only`](#only--except)                     | Control when jobs are created. |
+| [`pages`](#pages)                           | Upload the result of a job to use with GitLab Pages. |
+| [`parallel`](#parallel)                     | How many instances of a job should be run in parallel. |
+| [`release`](#release)                       | Instructs the runner to generate a [release](../../user/project/releases/index.md) object. |
+| [`resource_group`](#resource_group)         | Limit job concurrency. |
+| [`retry`](#retry)                           | When and how many times a job can be auto-retried in case of a failure. |
+| [`rules`](#rules)                           | List of conditions to evaluate and determine selected attributes of a job, and whether or not it's created. |
+| [`script`](#script)                         | Shell script that is executed by a runner. |
+| [`secrets`](#secrets)                       | The CI/CD secrets the job needs. |
+| [`services`](#services)                     | Use Docker services images. |
+| [`stage`](#stage)                           | Defines a job stage. |
+| [`tags`](#tags)                             | List of tags that are used to select a runner. |
+| [`timeout`](#timeout)                       | Define a custom job-level timeout that takes precedence over the project-wide setting. |
+| [`trigger`](#trigger)                       | Defines a downstream pipeline trigger. |
+| [`variables`](#variables)                   | Define job variables on a job level. |
+| [`when`](#when)                             | When to run job. |
 
 ### Unavailable names for jobs
 
@@ -4502,6 +4503,50 @@ You can use [CI/CD variables](../variables/index.md) to configure how the runner
 You can also use variables to configure how many times a runner
 [attempts certain stages of job execution](../runners/configure_runners.md#job-stages-attempts).
 
+## `dast_configuration` **(ULTIMATE)**
+
+> [Introduced](https://gitlab.com/groups/gitlab-org/-/epics/5981) in GitLab 14.1.
+
+Use the `dast_configuration` keyword to specify a site profile and scanner profile to be used in a
+CI/CD configuration. Both profiles must first have been created in the project. The job's stage must
+be `dast`.
+
+**Keyword type**: Job keyword. You can use only as part of a job.
+
+**Possible inputs**: One each of `site_profile` and `scanner_profile`.
+
+- Use `site_profile` to specify the site profile to be used in the job.
+- Use `scanner_profile` to specify the scanner profile to be used in the job.
+
+**Example of `dast_configuration`**:
+
+```yaml
+stages:
+  - build
+  - dast
+
+include:
+  - template: DAST.gitlab-ci.yml
+
+dast:
+  dast_configuration:
+    site_profile: "Example Co"
+    scanner_profile: "Quick Passive Test"
+```
+
+In this example, the `dast` job extends the `dast` configuration added with the `include:` keyword
+to select a specific site profile and scanner profile.
+
+**Additional details**:
+
+- Settings contained in either a site profile or scanner profile take precedence over those
+  contained in the DAST template.
+
+**Related topics**:
+
+- [Site profile](../../user/application_security/dast/index.md#site-profile).
+- [Scanner profile](../../user/application_security/dast/index.md#scanner-profile).
+
 ## YAML-specific features
 
 In your `.gitlab-ci.yml` file, you can use YAML-specific features like anchors (`&`), aliases (`*`),
diff --git a/doc/development/fe_guide/storybook.md b/doc/development/fe_guide/storybook.md
index 986eafb11da..15225cc1deb 100644
--- a/doc/development/fe_guide/storybook.md
+++ b/doc/development/fe_guide/storybook.md
@@ -47,5 +47,5 @@ To add a story:
 
    Notes:
    - Specify the `title` field of the story as the component's file path from the `javascripts/` directory,
-     e.g. if the component is located at `app/assets/javascripts/vue_shared/components/sidebar/todo_button.vue`, specify the `title` as
+     e.g. if the component is located at `app/assets/javascripts/vue_shared/components/sidebar/todo_toggle/todo_button.vue`, specify the `title` as
      `vue_shared/components/To-do Button`. This will ensure the Storybook navigation maps closely to our internal directory structure.
diff --git a/doc/user/application_security/dast/index.md b/doc/user/application_security/dast/index.md
index fa766f836e6..4b10f03fec3 100644
--- a/doc/user/application_security/dast/index.md
+++ b/doc/user/application_security/dast/index.md
@@ -145,6 +145,7 @@ To enable DAST to run automatically, either:
   by [Auto DevOps](../../../topics/autodevops/index.md)).
 - [Include the DAST template](#include-the-dast-template) in your existing
   `.gitlab-ci.yml` file.
+- [Configure DAST using the UI](#configure-dast-using-the-ui).
 
 ### DAST job order
 
@@ -265,6 +266,28 @@ image. Using the `DAST_VERSION` variable, you can choose how DAST updates:
 Find the latest DAST versions on the [Releases](https://gitlab.com/security-products/dast/-/releases)
 page.
 
+#### Configure DAST using the UI
+
+You can enable or configure DAST settings using the UI. The generated settings are formatted so they
+can be conveniently pasted into the `.gitlab-ci.yml` file.
+
+1. From the project's home page, go to **Security & Compliance > Configuration**.
+1. In the **Dynamic Application Security Testing (DAST)** section, select **Enable DAST** or
+   **Configure DAST**.
+1. Select the desired **Scanner profile**, or select **Create scanner profile** and save a
+   scanner profile. For more details, see [scanner profiles](#scanner-profile).
+1. Select the desired **Site profile**, or select **Create site profile** and save a site
+   profile. For more details, see [site profiles](#site-profile).
+1. Select **Generate code snippet**. A modal opens with the YAML snippet corresponding to the
+   options you selected.
+1. Do one of the following:
+   1. Select **Copy code only** to copy the snippet to your clipboard.
+   1. Select **Copy code and open `.gitlab-ci.yml` file** to copy the snippet to your clipboard. The
+   CI/CD Editor then opens.
+      1. Paste the snippet into the `.gitlab-ci.yml` file.
+      1. Select the **Lint** tab to confirm the edited `.gitlab-ci.yml` file is valid.
+      1. Select **Commit changes**.
+
 #### Crawling web applications dependent on JavaScript
 
 GitLab has released a new browser-based crawler, an add-on to DAST that uses a browser to crawl web applications for content. This crawler replaces the standard DAST Spider and Ajax Crawler, and uses the same authentication mechanisms as a normal DAST scan.
diff --git a/doc/user/project/merge_requests/approvals/settings.md b/doc/user/project/merge_requests/approvals/settings.md
index b72a4125d0e..8a81ff8c94b 100644
--- a/doc/user/project/merge_requests/approvals/settings.md
+++ b/doc/user/project/merge_requests/approvals/settings.md
@@ -115,8 +115,16 @@ permission enables an electronic signature for approvals, such as the one define
 ## Security approvals in merge requests **(ULTIMATE)**
 
 You can require that a member of your security team approves a merge request if a
-merge request could introduce a vulnerability. To learn more, see
-[Security approvals in merge requests](../../../application_security/index.md#security-approvals-in-merge-requests).
+merge request could introduce a vulnerability.
+
+To learn more, see [Security approvals in merge requests](../../../application_security/index.md#security-approvals-in-merge-requests).
+
+## Code coverage check approvals **(PREMIUM)**
+
+You can require specific approvals if a merge request would result in a decline in code test
+coverage.
+
+To learn more, see [Coverage check approval rule](../../../../ci/pipelines/settings.md#coverage-check-approval-rule).
 
 ## Related links
 
diff --git a/lib/api/entities/project_integration.rb b/lib/api/entities/project_integration.rb
new file mode 100644
index 00000000000..649e4d015b8
--- /dev/null
+++ b/lib/api/entities/project_integration.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module API
+  module Entities
+    class ProjectIntegration < Entities::ProjectIntegrationBasic
+      # Expose serialized properties
+      expose :properties do |integration, options|
+        # TODO: Simplify as part of https://gitlab.com/gitlab-org/gitlab/issues/29404
+
+        attributes =
+          if integration.data_fields_present?
+            integration.data_fields.as_json.keys
+          else
+            integration.properties.keys
+          end
+
+        attributes &= integration.api_field_names
+
+        attributes.each_with_object({}) do |attribute, hash|
+          hash[attribute] = integration.public_send(attribute) # rubocop:disable GitlabSecurity/PublicSend
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/entities/project_service_basic.rb b/lib/api/entities/project_integration_basic.rb
similarity index 77%
rename from lib/api/entities/project_service_basic.rb
rename to lib/api/entities/project_integration_basic.rb
index eb97ca69a82..2870123b83d 100644
--- a/lib/api/entities/project_service_basic.rb
+++ b/lib/api/entities/project_integration_basic.rb
@@ -2,10 +2,10 @@
 
 module API
   module Entities
-    class ProjectServiceBasic < Grape::Entity
+    class ProjectIntegrationBasic < Grape::Entity
       expose :id, :title
-      expose :slug do |service|
-        service.to_param.dasherize
+      expose :slug do |integration|
+        integration.to_param.dasherize
       end
       expose :created_at, :updated_at, :active
       expose :commit_events, :push_events, :issues_events, :confidential_issues_events
diff --git a/lib/api/entities/project_service.rb b/lib/api/entities/project_service.rb
deleted file mode 100644
index 07abf23660d..00000000000
--- a/lib/api/entities/project_service.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-# frozen_string_literal: true
-
-module API
-  module Entities
-    class ProjectService < Entities::ProjectServiceBasic
-      # Expose serialized properties
-      expose :properties do |service, options|
-        # TODO: Simplify as part of https://gitlab.com/gitlab-org/gitlab/issues/29404
-
-        attributes =
-          if service.data_fields_present?
-            service.data_fields.as_json.keys
-          else
-            service.properties.keys
-          end
-
-        attributes &= service.api_field_names
-
-        attributes.each_with_object({}) do |attribute, hash|
-          hash[attribute] = service.public_send(attribute) # rubocop:disable GitlabSecurity/PublicSend
-        end
-      end
-    end
-  end
-end
diff --git a/lib/api/services.rb b/lib/api/services.rb
index 6c21a80509d..a37b6f4626a 100644
--- a/lib/api/services.rb
+++ b/lib/api/services.rb
@@ -35,7 +35,7 @@ module API
       end
     end
 
-    TRIGGER_SERVICES = {
+    TRIGGER_INTEGRATIONS = {
       'mattermost-slash-commands' => [
         {
           name: :token,
@@ -60,24 +60,24 @@ module API
       before { authorize_admin_project }
 
       helpers do
-        def service_attributes(service)
-          service.fields.inject([]) do |arr, hash|
+        def integration_attributes(integration)
+          integration.fields.inject([]) do |arr, hash|
             arr << hash[:name].to_sym
           end
         end
       end
 
-      desc 'Get all active project services' do
-        success Entities::ProjectServiceBasic
+      desc 'Get all active project integrations' do
+        success Entities::ProjectIntegrationBasic
       end
       get ":id/services" do
-        services = user_project.integrations.active
+        integrations = user_project.integrations.active
 
-        present services, with: Entities::ProjectServiceBasic
+        present integrations, with: Entities::ProjectIntegrationBasic
       end
 
       INTEGRATIONS.each do |slug, settings|
-        desc "Set #{slug} service for project"
+        desc "Set #{slug} integration for project"
         params do
           settings.each do |setting|
             if setting[:required]
@@ -92,7 +92,7 @@ module API
           params = declared_params(include_missing: false).merge(active: true)
 
           if integration.update(params)
-            present integration, with: Entities::ProjectService
+            present integration, with: Entities::ProjectIntegration
           else
             render_api_error!('400 Bad Request', 400)
           end
@@ -107,14 +107,14 @@ module API
         integration = user_project.find_or_initialize_integration(params[:slug].underscore)
 
         destroy_conditionally!(integration) do
-          attrs = service_attributes(integration).index_with { nil }.merge(active: false)
+          attrs = integration_attributes(integration).index_with { nil }.merge(active: false)
 
           render_api_error!('400 Bad Request', 400) unless integration.update(attrs)
         end
       end
 
       desc 'Get the integration settings for a project' do
-        success Entities::ProjectService
+        success Entities::ProjectIntegration
       end
       params do
         requires :slug, type: String, values: INTEGRATIONS.keys, desc: 'The name of the service'
@@ -124,15 +124,15 @@ module API
 
         not_found!('Service') unless integration&.persisted?
 
-        present integration, with: Entities::ProjectService
+        present integration, with: Entities::ProjectIntegration
       end
     end
 
-    TRIGGER_SERVICES.each do |service_slug, settings|
+    TRIGGER_INTEGRATIONS.each do |integration_slug, settings|
       helpers do
-        def slash_command_service(project, service_slug, params)
-          project.integrations.active.find do |service|
-            service.try(:token) == params[:token] && service.to_param == service_slug.underscore
+        def slash_command_integration(project, integration_slug, params)
+          project.integrations.active.find do |integration|
+            integration.try(:token) == params[:token] && integration.to_param == integration_slug.underscore
           end
         end
       end
@@ -141,7 +141,7 @@ module API
         requires :id, type: String, desc: 'The ID of a project'
       end
       resource :projects, requirements: API::NAMESPACE_OR_PROJECT_REQUIREMENTS do
-        desc "Trigger a slash command for #{service_slug}" do
+        desc "Trigger a slash command for #{integration_slug}" do
           detail 'Added in GitLab 8.13'
         end
         params do
@@ -149,14 +149,14 @@ module API
             requires setting[:name], type: setting[:type], desc: setting[:desc]
           end
         end
-        post ":id/services/#{service_slug.underscore}/trigger" do
+        post ":id/services/#{integration_slug.underscore}/trigger" do
           project = find_project(params[:id])
 
           # This is not accurate, but done to prevent leakage of the project names
           not_found!('Service') unless project
 
-          service = slash_command_service(project, service_slug, params)
-          result = service.try(:trigger, params)
+          integration = slash_command_integration(project, integration_slug, params)
+          result = integration.try(:trigger, params)
 
           if result
             status result[:status] || 200
diff --git a/lib/gitlab/analytics/cycle_analytics/stage_events/stage_event.rb b/lib/gitlab/analytics/cycle_analytics/stage_events/stage_event.rb
index 530e53f9d10..8eb067ed0ec 100644
--- a/lib/gitlab/analytics/cycle_analytics/stage_events/stage_event.rb
+++ b/lib/gitlab/analytics/cycle_analytics/stage_events/stage_event.rb
@@ -31,6 +31,10 @@ module Gitlab
             raise NotImplementedError
           end
 
+          def hash_code
+            Digest::SHA256.hexdigest(self.class.identifier.to_s)
+          end
+
           # Each StageEvent must expose a timestamp or a timestamp like expression in order to build a range query.
           # Example: get me all the Issue records between start event end end event
           def timestamp_projection
diff --git a/lib/gitlab/checks/lfs_check.rb b/lib/gitlab/checks/lfs_check.rb
index 51013b69755..84069a1249b 100644
--- a/lib/gitlab/checks/lfs_check.rb
+++ b/lib/gitlab/checks/lfs_check.rb
@@ -7,9 +7,9 @@ module Gitlab
       ERROR_MESSAGE = 'LFS objects are missing. Ensure LFS is properly set up or try a manual "git lfs push --all".'
 
       def validate!
-        # This feature flag is used for disabling integrify check on some envs
+        # This feature flag is used for disabling integrity check on some envs
         # because these costy calculations may cause performance issues
-        return unless Feature.enabled?(:lfs_check, default_enabled: true)
+        return unless Feature.enabled?(:lfs_check, project, default_enabled: :yaml)
 
         return unless project.lfs_enabled?
 
diff --git a/lib/gitlab/diff/file_collection/commit.rb b/lib/gitlab/diff/file_collection/commit.rb
index 7b1d6171e82..0f8f408d326 100644
--- a/lib/gitlab/diff/file_collection/commit.rb
+++ b/lib/gitlab/diff/file_collection/commit.rb
@@ -10,6 +10,10 @@ module Gitlab
             diff_options: diff_options,
             diff_refs: commit.diff_refs)
         end
+
+        def cache_key
+          ['commit', @diffable.id]
+        end
       end
     end
   end
diff --git a/lib/gitlab/diff/file_collection/compare.rb b/lib/gitlab/diff/file_collection/compare.rb
index 663bad95db7..badebabb192 100644
--- a/lib/gitlab/diff/file_collection/compare.rb
+++ b/lib/gitlab/diff/file_collection/compare.rb
@@ -14,6 +14,10 @@ module Gitlab
         def unfold_diff_lines(positions)
           # no-op
         end
+
+        def cache_key
+          ['compare', @diffable.head.id, @diffable.base.id]
+        end
       end
     end
   end
diff --git a/lib/gitlab/diff/file_collection/merge_request_diff_base.rb b/lib/gitlab/diff/file_collection/merge_request_diff_base.rb
index 0c68a57daab..692186fc323 100644
--- a/lib/gitlab/diff/file_collection/merge_request_diff_base.rb
+++ b/lib/gitlab/diff/file_collection/merge_request_diff_base.rb
@@ -6,6 +6,8 @@ module Gitlab
       class MergeRequestDiffBase < Base
         extend ::Gitlab::Utils::Override
 
+        delegate :real_size, :overflow?, :cache_key, to: :@merge_request_diff
+
         def initialize(merge_request_diff, diff_options:)
           @merge_request_diff = merge_request_diff
 
@@ -44,14 +46,6 @@ module Gitlab
           diff_stats_cache.clear
         end
 
-        def real_size
-          @merge_request_diff.real_size
-        end
-
-        def overflow?
-          @merge_request_diff.overflow?
-        end
-
         private
 
         def highlight_cache
@@ -62,7 +56,7 @@ module Gitlab
 
         def diff_stats_cache
           strong_memoize(:diff_stats_cache) do
-            Gitlab::Diff::StatsCache.new(cachable_key: @merge_request_diff.cache_key)
+            Gitlab::Diff::StatsCache.new(cachable_key: cache_key)
           end
         end
 
diff --git a/lib/gitlab/git/repository.rb b/lib/gitlab/git/repository.rb
index 2ace857d336..3d84e34297b 100644
--- a/lib/gitlab/git/repository.rb
+++ b/lib/gitlab/git/repository.rb
@@ -883,12 +883,6 @@ module Gitlab
         end
       end
 
-      def rebase_in_progress?(rebase_id)
-        wrapped_gitaly_errors do
-          gitaly_repository_client.rebase_in_progress?(rebase_id)
-        end
-      end
-
       def squash(user, squash_id, start_sha:, end_sha:, author:, message:)
         wrapped_gitaly_errors do
           gitaly_operation_client.user_squash(user, squash_id, start_sha, end_sha, author, message)
diff --git a/lib/gitlab/gitaly_client/repository_service.rb b/lib/gitlab/gitaly_client/repository_service.rb
index 6a75096ff80..009aeaf868a 100644
--- a/lib/gitlab/gitaly_client/repository_service.rb
+++ b/lib/gitlab/gitaly_client/repository_service.rb
@@ -152,23 +152,6 @@ module Gitlab
         )
       end
 
-      def rebase_in_progress?(rebase_id)
-        request = Gitaly::IsRebaseInProgressRequest.new(
-          repository: @gitaly_repo,
-          rebase_id: rebase_id.to_s
-        )
-
-        response = GitalyClient.call(
-          @storage,
-          :repository_service,
-          :is_rebase_in_progress,
-          request,
-          timeout: GitalyClient.fast_timeout
-        )
-
-        response.in_progress
-      end
-
       def squash_in_progress?(squash_id)
         request = Gitaly::IsSquashInProgressRequest.new(
           repository: @gitaly_repo,
diff --git a/spec/frontend/boards/components/board_content_sidebar_spec.js b/spec/frontend/boards/components/board_content_sidebar_spec.js
index 614aa69e827..8a8250205d0 100644
--- a/spec/frontend/boards/components/board_content_sidebar_spec.js
+++ b/spec/frontend/boards/components/board_content_sidebar_spec.js
@@ -10,7 +10,8 @@ import BoardSidebarTitle from '~/boards/components/sidebar/board_sidebar_title.v
 import { ISSUABLE } from '~/boards/constants';
 import SidebarDateWidget from '~/sidebar/components/date/sidebar_date_widget.vue';
 import SidebarSubscriptionsWidget from '~/sidebar/components/subscriptions/sidebar_subscriptions_widget.vue';
-import { mockIssue, mockIssueGroupPath, mockIssueProjectPath } from '../mock_data';
+import SidebarTodoWidget from '~/sidebar/components/todo_toggle/sidebar_todo_widget.vue';
+import { mockActiveIssue, mockIssue, mockIssueGroupPath, mockIssueProjectPath } from '../mock_data';
 
 describe('BoardContentSidebar', () => {
   let wrapper;
@@ -26,7 +27,7 @@ describe('BoardContentSidebar', () => {
       },
       getters: {
         activeBoardItem: () => {
-          return { ...mockIssue, epic: null };
+          return { ...mockActiveIssue, epic: null };
         },
         groupPathForActiveIssue: () => mockIssueGroupPath,
         projectPathForActiveIssue: () => mockIssueProjectPath,
@@ -110,6 +111,10 @@ describe('BoardContentSidebar', () => {
     expect(wrapper.findComponent(GlDrawer).props('open')).toBe(true);
   });
 
+  it('renders SidebarTodoWidget', () => {
+    expect(wrapper.findComponent(SidebarTodoWidget).exists()).toBe(true);
+  });
+
   it('renders BoardSidebarLabelsSelect', () => {
     expect(wrapper.findComponent(BoardSidebarLabelsSelect).exists()).toBe(true);
   });
@@ -147,7 +152,7 @@ describe('BoardContentSidebar', () => {
 
       expect(toggleBoardItem).toHaveBeenCalledTimes(1);
       expect(toggleBoardItem).toHaveBeenCalledWith(expect.any(Object), {
-        boardItem: { ...mockIssue, epic: null },
+        boardItem: { ...mockActiveIssue, epic: null },
         sidebarType: ISSUABLE,
       });
     });
diff --git a/spec/frontend/boards/components/board_content_spec.js b/spec/frontend/boards/components/board_content_spec.js
index 8c1a7bd3947..5a799b6388e 100644
--- a/spec/frontend/boards/components/board_content_spec.js
+++ b/spec/frontend/boards/components/board_content_spec.js
@@ -1,5 +1,6 @@
 import { GlAlert } from '@gitlab/ui';
-import { createLocalVue, shallowMount } from '@vue/test-utils';
+import { shallowMount } from '@vue/test-utils';
+import Vue from 'vue';
 import Draggable from 'vuedraggable';
 import Vuex from 'vuex';
 import EpicsSwimlanes from 'ee_component/boards/components/epics_swimlanes.vue';
@@ -8,8 +9,7 @@ import BoardColumnDeprecated from '~/boards/components/board_column_deprecated.v
 import BoardContent from '~/boards/components/board_content.vue';
 import { mockLists, mockListsWithModel } from '../mock_data';
 
-const localVue = createLocalVue();
-localVue.use(Vuex);
+Vue.use(Vuex);
 
 const actions = {
   moveList: jest.fn(),
@@ -44,7 +44,6 @@ describe('BoardContent', () => {
       ...state,
     });
     wrapper = shallowMount(BoardContent, {
-      localVue,
       propsData: {
         lists: mockListsWithModel,
         disabled: false,
diff --git a/spec/frontend/boards/mock_data.js b/spec/frontend/boards/mock_data.js
index 8bc80fc2007..73372eafb89 100644
--- a/spec/frontend/boards/mock_data.js
+++ b/spec/frontend/boards/mock_data.js
@@ -182,6 +182,7 @@ export const mockIssue = {
 
 export const mockActiveIssue = {
   ...mockIssue,
+  fullId: 'gid://gitlab/Issue/436',
   id: 436,
   iid: '27',
   subscribed: false,
diff --git a/spec/frontend/collapsed_sidebar_todo_spec.js b/spec/frontend/collapsed_sidebar_todo_spec.js
deleted file mode 100644
index 7c659822672..00000000000
--- a/spec/frontend/collapsed_sidebar_todo_spec.js
+++ /dev/null
@@ -1,171 +0,0 @@
-/* eslint-disable no-new */
-import MockAdapter from 'axios-mock-adapter';
-import { clone } from 'lodash';
-import waitForPromises from 'helpers/wait_for_promises';
-import { TEST_HOST } from 'spec/test_constants';
-import axios from '~/lib/utils/axios_utils';
-import Sidebar from '~/right_sidebar';
-import { fixTitle } from '~/tooltips';
-
-jest.mock('~/tooltips');
-
-describe('Issuable right sidebar collapsed todo toggle', () => {
-  const fixtureName = 'issues/open-issue.html';
-  const jsonFixtureName = 'todos/todos.json';
-  let mock;
-
-  beforeEach(() => {
-    const todoData = getJSONFixture(jsonFixtureName);
-    new Sidebar();
-    loadFixtures(fixtureName);
-
-    document.querySelector('.js-right-sidebar').classList.toggle('right-sidebar-expanded');
-    document.querySelector('.js-right-sidebar').classList.toggle('right-sidebar-collapsed');
-
-    mock = new MockAdapter(axios);
-
-    mock.onPost(`${TEST_HOST}/frontend-fixtures/issues-project/todos`).reply(() => {
-      const response = clone(todoData);
-
-      return [200, response];
-    });
-
-    mock.onDelete(/(.*)\/dashboard\/todos\/\d+$/).reply(() => {
-      const response = clone(todoData);
-      delete response.delete_path;
-
-      return [200, response];
-    });
-  });
-
-  afterEach(() => {
-    mock.restore();
-  });
-
-  it('shows add todo button', () => {
-    expect(document.querySelector('.js-issuable-todo.sidebar-collapsed-icon')).not.toBeNull();
-
-    expect(
-      document
-        .querySelector('.js-issuable-todo.sidebar-collapsed-icon svg')
-        .getAttribute('data-testid'),
-    ).toBe('todo-add-icon');
-
-    expect(
-      document.querySelector('.js-issuable-todo.sidebar-collapsed-icon .todo-undone'),
-    ).toBeNull();
-  });
-
-  it('sets default tooltip title', () => {
-    expect(
-      document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').getAttribute('title'),
-    ).toBe('Add a to do');
-  });
-
-  it('toggle todo state', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    setImmediate(() => {
-      expect(
-        document.querySelector('.js-issuable-todo.sidebar-collapsed-icon .todo-undone'),
-      ).not.toBeNull();
-
-      expect(
-        document
-          .querySelector('.js-issuable-todo.sidebar-collapsed-icon svg.todo-undone')
-          .getAttribute('data-testid'),
-      ).toBe('todo-done-icon');
-
-      done();
-    });
-  });
-
-  it('toggle todo state of expanded todo toggle', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    setImmediate(() => {
-      expect(
-        document.querySelector('.issuable-sidebar-header .js-issuable-todo').textContent.trim(),
-      ).toBe('Mark as done');
-
-      done();
-    });
-  });
-
-  it('toggles todo button tooltip', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    setImmediate(() => {
-      const el = document.querySelector('.js-issuable-todo.sidebar-collapsed-icon');
-
-      expect(el.getAttribute('title')).toBe('Mark as done');
-      expect(fixTitle).toHaveBeenCalledWith(el);
-
-      done();
-    });
-  });
-
-  it('marks todo as done', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    waitForPromises()
-      .then(() => {
-        expect(
-          document.querySelector('.js-issuable-todo.sidebar-collapsed-icon .todo-undone'),
-        ).not.toBeNull();
-
-        document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-      })
-      .then(waitForPromises)
-      .then(() => {
-        expect(
-          document.querySelector('.js-issuable-todo.sidebar-collapsed-icon .todo-undone'),
-        ).toBeNull();
-
-        expect(
-          document.querySelector('.issuable-sidebar-header .js-issuable-todo').textContent.trim(),
-        ).toBe('Add a to do');
-      })
-      .then(done)
-      .catch(done.fail);
-  });
-
-  it('updates aria-label to Mark as done', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    setImmediate(() => {
-      expect(
-        document
-          .querySelector('.js-issuable-todo.sidebar-collapsed-icon')
-          .getAttribute('aria-label'),
-      ).toBe('Mark as done');
-
-      done();
-    });
-  });
-
-  it('updates aria-label to add todo', (done) => {
-    document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-
-    waitForPromises()
-      .then(() => {
-        expect(
-          document
-            .querySelector('.js-issuable-todo.sidebar-collapsed-icon')
-            .getAttribute('aria-label'),
-        ).toBe('Mark as done');
-
-        document.querySelector('.js-issuable-todo.sidebar-collapsed-icon').click();
-      })
-      .then(waitForPromises)
-      .then(() => {
-        expect(
-          document
-            .querySelector('.js-issuable-todo.sidebar-collapsed-icon')
-            .getAttribute('aria-label'),
-        ).toBe('Add a to do');
-      })
-      .then(done)
-      .catch(done.fail);
-  });
-});
diff --git a/spec/frontend/design_management/components/design_todo_button_spec.js b/spec/frontend/design_management/components/design_todo_button_spec.js
index 816de32d2db..757bf50c527 100644
--- a/spec/frontend/design_management/components/design_todo_button_spec.js
+++ b/spec/frontend/design_management/components/design_todo_button_spec.js
@@ -2,7 +2,7 @@ import { shallowMount, mount } from '@vue/test-utils';
 import DesignTodoButton from '~/design_management/components/design_todo_button.vue';
 import createDesignTodoMutation from '~/design_management/graphql/mutations/create_design_todo.mutation.graphql';
 import todoMarkDoneMutation from '~/graphql_shared/mutations/todo_mark_done.mutation.graphql';
-import TodoButton from '~/vue_shared/components/sidebar/todo_button.vue';
+import TodoButton from '~/vue_shared/components/sidebar/todo_toggle/todo_button.vue';
 import mockDesign from '../mock_data/design';
 
 const mockDesignWithPendingTodos = {
diff --git a/spec/frontend/right_sidebar_spec.js b/spec/frontend/right_sidebar_spec.js
index 8699e1cf420..d1f861669a0 100644
--- a/spec/frontend/right_sidebar_spec.js
+++ b/spec/frontend/right_sidebar_spec.js
@@ -66,22 +66,6 @@ describe('RightSidebar', () => {
       assertSidebarState('collapsed');
     });
 
-    it('should broadcast todo:toggle event when add todo clicked', (done) => {
-      const todos = getJSONFixture('todos/todos.json');
-      mock.onPost(/(.*)\/todos$/).reply(200, todos);
-
-      const todoToggleSpy = jest.fn();
-      $(document).on('todo:toggle', todoToggleSpy);
-
-      $('.issuable-sidebar-header .js-issuable-todo').click();
-
-      setImmediate(() => {
-        expect(todoToggleSpy.mock.calls.length).toEqual(1);
-
-        done();
-      });
-    });
-
     it('should not hide collapsed icons', () => {
       [].forEach.call(document.querySelectorAll('.sidebar-collapsed-icon'), (el) => {
         expect(el.querySelector('.fa, svg').classList.contains('hidden')).toBeFalsy();
diff --git a/spec/frontend/sidebar/components/todo_toggle/sidebar_todo_widget_spec.js b/spec/frontend/sidebar/components/todo_toggle/sidebar_todo_widget_spec.js
index 2aecc2e0142..23f1753c4bf 100644
--- a/spec/frontend/sidebar/components/todo_toggle/sidebar_todo_widget_spec.js
+++ b/spec/frontend/sidebar/components/todo_toggle/sidebar_todo_widget_spec.js
@@ -1,3 +1,4 @@
+import { GlIcon } from '@gitlab/ui';
 import { shallowMount } from '@vue/test-utils';
 import Vue from 'vue';
 import VueApollo from 'vue-apollo';
@@ -6,7 +7,7 @@ import waitForPromises from 'helpers/wait_for_promises';
 import createFlash from '~/flash';
 import SidebarTodoWidget from '~/sidebar/components/todo_toggle/sidebar_todo_widget.vue';
 import epicTodoQuery from '~/sidebar/queries/epic_todo.query.graphql';
-import TodoButton from '~/vue_shared/components/sidebar/todo_button.vue';
+import TodoButton from '~/vue_shared/components/sidebar/todo_toggle/todo_button.vue';
 import { todosResponse, noTodosResponse } from '../../mock_data';
 
 jest.mock('~/flash');
@@ -28,6 +29,7 @@ describe('Sidebar Todo Widget', () => {
       apolloProvider: fakeApollo,
       provide: {
         canUpdate: true,
+        isClassicSidebar: true,
       },
       propsData: {
         fullPath: 'group',
@@ -83,4 +85,42 @@ describe('Sidebar Todo Widget', () => {
 
     expect(createFlash).toHaveBeenCalled();
   });
+
+  describe('collapsed', () => {
+    const event = { stopPropagation: jest.fn(), preventDefault: jest.fn() };
+
+    beforeEach(() => {
+      createComponent({
+        todosQueryHandler: jest.fn().mockResolvedValue(noTodosResponse),
+      });
+      return waitForPromises();
+    });
+
+    it('shows add todo icon', () => {
+      expect(wrapper.find(GlIcon).exists()).toBe(true);
+
+      expect(wrapper.find(GlIcon).props('name')).toBe('todo-add');
+    });
+
+    it('sets default tooltip title', () => {
+      expect(wrapper.find(GlIcon).attributes('title')).toBe('Add a to do');
+    });
+
+    it('when user has a to do', async () => {
+      createComponent({
+        todosQueryHandler: jest.fn().mockResolvedValue(todosResponse),
+      });
+
+      await waitForPromises();
+      expect(wrapper.find(GlIcon).props('name')).toBe('todo-done');
+      expect(wrapper.find(GlIcon).attributes('title')).toBe('Mark as done');
+    });
+
+    it('emits `todoUpdated` event on click on icon', async () => {
+      wrapper.find(GlIcon).vm.$emit('click', event);
+
+      await wrapper.vm.$nextTick();
+      expect(wrapper.emitted('todoUpdated')).toEqual([[false]]);
+    });
+  });
 });
diff --git a/spec/frontend/vue_shared/components/sidebar/todo_button_spec.js b/spec/frontend/vue_shared/components/sidebar/todo_button_spec.js
index 123a995ad57..de3e1ccfb03 100644
--- a/spec/frontend/vue_shared/components/sidebar/todo_button_spec.js
+++ b/spec/frontend/vue_shared/components/sidebar/todo_button_spec.js
@@ -1,6 +1,6 @@
 import { GlButton } from '@gitlab/ui';
 import { shallowMount, mount } from '@vue/test-utils';
-import TodoButton from '~/vue_shared/components/sidebar/todo_button.vue';
+import TodoButton from '~/vue_shared/components/sidebar/todo_toggle/todo_button.vue';
 
 describe('Todo Button', () => {
   let wrapper;
diff --git a/spec/lib/gitlab/diff/file_collection/commit_spec.rb b/spec/lib/gitlab/diff/file_collection/commit_spec.rb
index 3d995b36b6f..cfb5f50edbe 100644
--- a/spec/lib/gitlab/diff/file_collection/commit_spec.rb
+++ b/spec/lib/gitlab/diff/file_collection/commit_spec.rb
@@ -75,4 +75,12 @@ RSpec.describe Gitlab::Diff::FileCollection::Commit do
       ]
     end
   end
+
+  describe '#cache_key' do
+    subject(:cache_key) { described_class.new(diffable, diff_options: nil).cache_key }
+
+    it 'returns with the commit id' do
+      expect(cache_key).to eq ['commit', diffable.id]
+    end
+  end
 end
diff --git a/spec/lib/gitlab/diff/file_collection/compare_spec.rb b/spec/lib/gitlab/diff/file_collection/compare_spec.rb
index f3326f4f03d..ce70903a480 100644
--- a/spec/lib/gitlab/diff/file_collection/compare_spec.rb
+++ b/spec/lib/gitlab/diff/file_collection/compare_spec.rb
@@ -15,29 +15,20 @@ RSpec.describe Gitlab::Diff::FileCollection::Compare do
                              head_commit.id)
   end
 
-  it_behaves_like 'diff statistics' do
-    let(:collection_default_args) do
-      {
-        project: diffable.project,
-        diff_options: {},
-        diff_refs: diffable.diff_refs
-      }
-    end
+  let(:diffable) { Compare.new(raw_compare, project) }
+  let(:collection_default_args) do
+    {
+      project: diffable.project,
+      diff_options: {},
+      diff_refs: diffable.diff_refs
+    }
+  end
 
-    let(:diffable) { Compare.new(raw_compare, project) }
+  it_behaves_like 'diff statistics' do
     let(:stub_path) { '.gitignore' }
   end
 
   it_behaves_like 'sortable diff files' do
-    let(:diffable) { Compare.new(raw_compare, project) }
-    let(:collection_default_args) do
-      {
-        project: diffable.project,
-        diff_options: {},
-        diff_refs: diffable.diff_refs
-      }
-    end
-
     let(:unsorted_diff_files_paths) do
       [
         '.DS_Store',
@@ -66,4 +57,12 @@ RSpec.describe Gitlab::Diff::FileCollection::Compare do
       ]
     end
   end
+
+  describe '#cache_key' do
+    subject(:cache_key) { described_class.new(diffable, **collection_default_args).cache_key }
+
+    it 'returns with head and base' do
+      expect(cache_key).to eq ['compare', head_commit.id, start_commit.id]
+    end
+  end
 end
diff --git a/spec/lib/gitlab/diff/file_collection/merge_request_diff_base_spec.rb b/spec/lib/gitlab/diff/file_collection/merge_request_diff_base_spec.rb
index 022ee5504d6..51bee6d45e4 100644
--- a/spec/lib/gitlab/diff/file_collection/merge_request_diff_base_spec.rb
+++ b/spec/lib/gitlab/diff/file_collection/merge_request_diff_base_spec.rb
@@ -25,4 +25,12 @@ RSpec.describe Gitlab::Diff::FileCollection::MergeRequestDiffBase do
       end
     end
   end
+
+  describe '#cache_key' do
+    subject(:cache_key) { described_class.new(diffable, diff_options: nil).cache_key }
+
+    it 'returns cache_key from merge_request_diff' do
+      expect(cache_key).to eq diffable.cache_key
+    end
+  end
 end
diff --git a/spec/lib/gitlab/gitaly_client/repository_service_spec.rb b/spec/lib/gitlab/gitaly_client/repository_service_spec.rb
index 56c8fe20eca..53805d67f9f 100644
--- a/spec/lib/gitlab/gitaly_client/repository_service_spec.rb
+++ b/spec/lib/gitlab/gitaly_client/repository_service_spec.rb
@@ -209,19 +209,6 @@ RSpec.describe Gitlab::GitalyClient::RepositoryService do
     end
   end
 
-  describe '#rebase_in_progress?' do
-    let(:rebase_id) { 1 }
-
-    it 'sends a repository_rebase_in_progress message' do
-      expect_any_instance_of(Gitaly::RepositoryService::Stub)
-        .to receive(:is_rebase_in_progress)
-        .with(gitaly_request_with_path(storage_name, relative_path), kind_of(Hash))
-        .and_return(double(in_progress: true))
-
-      client.rebase_in_progress?(rebase_id)
-    end
-  end
-
   describe '#squash_in_progress?' do
     let(:squash_id) { 1 }
 
diff --git a/spec/models/diff_discussion_spec.rb b/spec/models/diff_discussion_spec.rb
index 2a2663149d0..998204626d3 100644
--- a/spec/models/diff_discussion_spec.rb
+++ b/spec/models/diff_discussion_spec.rb
@@ -126,4 +126,13 @@ RSpec.describe DiffDiscussion do
       end
     end
   end
+
+  describe '#cache_key' do
+    it 'returns the cache key with the position sha' do
+      notes_sha = Digest::SHA1.hexdigest("#{diff_note.id}")
+      position_sha = Digest::SHA1.hexdigest(diff_note.position.to_json)
+
+      expect(subject.cache_key).to eq("#{described_class::CACHE_VERSION}:#{diff_note.latest_cached_markdown_version}:#{subject.id}:#{notes_sha}:#{diff_note.updated_at}::#{position_sha}")
+    end
+  end
 end
diff --git a/spec/requests/api/services_spec.rb b/spec/requests/api/services_spec.rb
index 581fef20b62..e550132e776 100644
--- a/spec/requests/api/services_spec.rb
+++ b/spec/requests/api/services_spec.rb
@@ -31,7 +31,7 @@ RSpec.describe API::Services do
       it "returns a list of all active integrations" do
         get api("/projects/#{project.id}/services", user)
 
-        aggregate_failures 'expect successful response with all active services' do
+        aggregate_failures 'expect successful response with all active integrations' do
           expect(response).to have_gitlab_http_status(:ok)
           expect(json_response).to be_an Array
           expect(json_response.count).to eq(1)
@@ -42,40 +42,38 @@ RSpec.describe API::Services do
     end
   end
 
-  Integration.available_integration_names.each do |service|
-    describe "PUT /projects/:id/services/#{service.dasherize}" do
-      include_context service
+  Integration.available_integration_names.each do |integration|
+    describe "PUT /projects/:id/services/#{integration.dasherize}" do
+      include_context integration
 
-      it "updates #{service} settings" do
-        put api("/projects/#{project.id}/services/#{dashed_service}", user), params: service_attrs
+      it "updates #{integration} settings" do
+        put api("/projects/#{project.id}/services/#{dashed_integration}", user), params: integration_attrs
 
         expect(response).to have_gitlab_http_status(:ok)
 
-        current_service = project.integrations.first
-        events = current_service.event_names.empty? ? ["foo"].freeze : current_service.event_names
+        current_integration = project.integrations.first
+        events = current_integration.event_names.empty? ? ["foo"].freeze : current_integration.event_names
         query_strings = []
         events.each do |event|
-          query_strings << "#{event}=#{!current_service[event]}"
+          query_strings << "#{event}=#{!current_integration[event]}"
         end
         query_strings = query_strings.join('&')
 
-        put api("/projects/#{project.id}/services/#{dashed_service}?#{query_strings}", user), params: service_attrs
+        put api("/projects/#{project.id}/services/#{dashed_integration}?#{query_strings}", user), params: integration_attrs
 
         expect(response).to have_gitlab_http_status(:ok)
-        expect(json_response['slug']).to eq(dashed_service)
+        expect(json_response['slug']).to eq(dashed_integration)
         events.each do |event|
           next if event == "foo"
 
-          expect(project.integrations.first[event]).not_to eq(current_service[event]),
-            "expected #{!current_service[event]} for event #{event} for service #{current_service.title}, got #{current_service[event]}"
+          expect(project.integrations.first[event]).not_to eq(current_integration[event]),
+            "expected #{!current_integration[event]} for event #{event} for service #{current_integration.title}, got #{current_integration[event]}"
         end
       end
 
       it "returns if required fields missing" do
-        attrs = service_attrs
-
-        required_attributes = service_attrs_list.select do |attr|
-          service_klass.validators_on(attr).any? do |v|
+        required_attributes = integration_attrs_list.select do |attr|
+          integration_klass.validators_on(attr).any? do |v|
             v.instance_of?(ActiveRecord::Validations::PresenceValidator) &&
             # exclude presence validators with conditional since those are not really required
             ![:if, :unless].any? { |cond| v.options.include?(cond) }
@@ -85,74 +83,74 @@ RSpec.describe API::Services do
         if required_attributes.empty?
           expected_code = :ok
         else
-          attrs.delete(required_attributes.sample)
+          integration_attrs.delete(required_attributes.sample)
           expected_code = :bad_request
         end
 
-        put api("/projects/#{project.id}/services/#{dashed_service}", user), params: attrs
+        put api("/projects/#{project.id}/services/#{dashed_integration}", user), params: integration_attrs
 
         expect(response).to have_gitlab_http_status(expected_code)
       end
     end
 
-    describe "DELETE /projects/:id/services/#{service.dasherize}" do
-      include_context service
+    describe "DELETE /projects/:id/services/#{integration.dasherize}" do
+      include_context integration
 
       before do
-        initialize_integration(service)
+        initialize_integration(integration)
       end
 
-      it "deletes #{service}" do
-        delete api("/projects/#{project.id}/services/#{dashed_service}", user)
+      it "deletes #{integration}" do
+        delete api("/projects/#{project.id}/services/#{dashed_integration}", user)
 
         expect(response).to have_gitlab_http_status(:no_content)
-        project.send(service_method).reload
-        expect(project.send(service_method).activated?).to be_falsey
+        project.send(integration_method).reload
+        expect(project.send(integration_method).activated?).to be_falsey
       end
     end
 
-    describe "GET /projects/:id/services/#{service.dasherize}" do
-      include_context service
+    describe "GET /projects/:id/services/#{integration.dasherize}" do
+      include_context integration
 
-      let!(:initialized_service) { initialize_integration(service, active: true) }
+      let!(:initialized_integration) { initialize_integration(integration, active: true) }
 
       let_it_be(:project2) do
         create(:project, creator_id: user.id, namespace: user.namespace)
       end
 
-      def deactive_service!
-        return initialized_service.update!(active: false) unless initialized_service.is_a?(::Integrations::Prometheus)
+      def deactive_integration!
+        return initialized_integration.update!(active: false) unless initialized_integration.is_a?(::Integrations::Prometheus)
 
         # Integrations::Prometheus sets `#active` itself within a `before_save`:
-        initialized_service.manual_configuration = false
-        initialized_service.save!
+        initialized_integration.manual_configuration = false
+        initialized_integration.save!
       end
 
       it 'returns authentication error when unauthenticated' do
-        get api("/projects/#{project.id}/services/#{dashed_service}")
+        get api("/projects/#{project.id}/services/#{dashed_integration}")
         expect(response).to have_gitlab_http_status(:unauthorized)
       end
 
-      it "returns all properties of active service #{service}" do
-        get api("/projects/#{project.id}/services/#{dashed_service}", user)
+      it "returns all properties of active service #{integration}" do
+        get api("/projects/#{project.id}/services/#{dashed_integration}", user)
 
-        expect(initialized_service).to be_active
+        expect(initialized_integration).to be_active
         expect(response).to have_gitlab_http_status(:ok)
-        expect(json_response['properties'].keys).to match_array(service_instance.api_field_names)
+        expect(json_response['properties'].keys).to match_array(integration_instance.api_field_names)
       end
 
-      it "returns all properties of inactive integration #{service}" do
-        deactive_service!
+      it "returns all properties of inactive integration #{integration}" do
+        deactive_integration!
 
-        get api("/projects/#{project.id}/services/#{dashed_service}", user)
+        get api("/projects/#{project.id}/services/#{dashed_integration}", user)
 
-        expect(initialized_service).not_to be_active
+        expect(initialized_integration).not_to be_active
         expect(response).to have_gitlab_http_status(:ok)
-        expect(json_response['properties'].keys).to match_array(service_instance.api_field_names)
+        expect(json_response['properties'].keys).to match_array(integration_instance.api_field_names)
       end
 
       it "returns not found if integration does not exist" do
-        get api("/projects/#{project2.id}/services/#{dashed_service}", user)
+        get api("/projects/#{project2.id}/services/#{dashed_integration}", user)
 
         expect(response).to have_gitlab_http_status(:not_found)
         expect(json_response['message']).to eq('404 Service Not Found')
@@ -160,10 +158,10 @@ RSpec.describe API::Services do
 
       it "returns not found if service exists but is in `Project#disabled_integrations`" do
         expect_next_found_instance_of(Project) do |project|
-          expect(project).to receive(:disabled_integrations).at_least(:once).and_return([service])
+          expect(project).to receive(:disabled_integrations).at_least(:once).and_return([integration])
         end
 
-        get api("/projects/#{project.id}/services/#{dashed_service}", user)
+        get api("/projects/#{project.id}/services/#{dashed_integration}", user)
 
         expect(response).to have_gitlab_http_status(:not_found)
         expect(json_response['message']).to eq('404 Service Not Found')
@@ -171,7 +169,7 @@ RSpec.describe API::Services do
 
       it "returns error when authenticated but not a project owner" do
         project.add_developer(user2)
-        get api("/projects/#{project.id}/services/#{dashed_service}", user2)
+        get api("/projects/#{project.id}/services/#{dashed_integration}", user2)
 
         expect(response).to have_gitlab_http_status(:forbidden)
       end
@@ -235,8 +233,8 @@ RSpec.describe API::Services do
       end
     end
 
-    describe 'Slack Service' do
-      let(:service_name) { 'slack_slash_commands' }
+    describe 'Slack Integration' do
+      let(:integration_name) { 'slack_slash_commands' }
 
       before do
         project.create_slack_slash_commands_integration(
@@ -246,7 +244,7 @@ RSpec.describe API::Services do
       end
 
       it 'returns status 200' do
-        post api("/projects/#{project.id}/services/#{service_name}/trigger"), params: { token: 'token', text: 'help' }
+        post api("/projects/#{project.id}/services/#{integration_name}/trigger"), params: { token: 'token', text: 'help' }
 
         expect(response).to have_gitlab_http_status(:ok)
         expect(json_response['response_type']).to eq("ephemeral")
@@ -309,8 +307,8 @@ RSpec.describe API::Services do
     end
   end
 
-  describe 'Hangouts Chat service' do
-    let(:service_name) { 'hangouts-chat' }
+  describe 'Hangouts Chat integration' do
+    let(:integration_name) { 'hangouts-chat' }
     let(:params) do
       {
         webhook: 'https://hook.example.com',
@@ -326,21 +324,21 @@ RSpec.describe API::Services do
     end
 
     it 'accepts branches_to_be_notified for update', :aggregate_failures do
-      put api("/projects/#{project.id}/services/#{service_name}", user), params: params.merge(branches_to_be_notified: 'all')
+      put api("/projects/#{project.id}/services/#{integration_name}", user), params: params.merge(branches_to_be_notified: 'all')
 
       expect(response).to have_gitlab_http_status(:ok)
       expect(json_response['properties']['branches_to_be_notified']).to eq('all')
     end
 
     it 'only requires the webhook param' do
-      put api("/projects/#{project.id}/services/#{service_name}", user), params: { webhook: 'https://hook.example.com' }
+      put api("/projects/#{project.id}/services/#{integration_name}", user), params: { webhook: 'https://hook.example.com' }
 
       expect(response).to have_gitlab_http_status(:ok)
     end
   end
 
   describe 'Pipelines Email Integration' do
-    let(:service_name) { 'pipelines-email' }
+    let(:integration_name) { 'pipelines-email' }
 
     context 'notify_only_broken_pipelines property was saved as a string' do
       before do
@@ -354,7 +352,7 @@ RSpec.describe API::Services do
       end
 
       it 'returns boolean values for notify_only_broken_pipelines' do
-        get api("/projects/#{project.id}/services/#{service_name}", user)
+        get api("/projects/#{project.id}/services/#{integration_name}", user)
 
         expect(json_response['properties']['notify_only_broken_pipelines']).to eq(true)
       end
diff --git a/spec/requests/projects/merge_requests/diffs_spec.rb b/spec/requests/projects/merge_requests/diffs_spec.rb
new file mode 100644
index 00000000000..3a64c88acc1
--- /dev/null
+++ b/spec/requests/projects/merge_requests/diffs_spec.rb
@@ -0,0 +1,126 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Merge Requests Diffs' do
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:merge_request) { create(:merge_request_with_diffs, target_project: project, source_project: project) }
+
+  before do
+    project.add_maintainer(user)
+    sign_in(user)
+  end
+
+  describe 'GET diffs_batch' do
+    let(:headers) { {} }
+
+    shared_examples_for 'serializes diffs with expected arguments' do
+      it 'serializes paginated merge request diff collection' do
+        expect_next_instance_of(PaginatedDiffSerializer) do |instance|
+          expect(instance).to receive(:represent)
+            .with(an_instance_of(collection), expected_options)
+            .and_call_original
+        end
+
+        subject
+      end
+    end
+
+    def collection_arguments(pagination_data = {})
+      {
+        environment: nil,
+        merge_request: merge_request,
+        diff_view: :inline,
+        merge_ref_head_diff: nil,
+        pagination_data: {
+          total_pages: nil
+        }.merge(pagination_data)
+      }
+    end
+
+    def go(extra_params = {})
+      params = {
+        namespace_id: project.namespace.to_param,
+        project_id: project,
+        id: merge_request.iid,
+        page: 0,
+        per_page: 20,
+        format: 'json'
+      }
+
+      get diffs_batch_namespace_project_json_merge_request_path(params.merge(extra_params)), headers: headers
+    end
+
+    context 'with caching', :use_clean_rails_memory_store_caching do
+      subject { go(page: 0, per_page: 5) }
+
+      context 'when the request has not been cached' do
+        it_behaves_like 'serializes diffs with expected arguments' do
+          let(:collection) { Gitlab::Diff::FileCollection::MergeRequestDiffBatch }
+          let(:expected_options) { collection_arguments(total_pages: 20) }
+        end
+      end
+
+      context 'when the request has already been cached' do
+        before do
+          go(page: 0, per_page: 5)
+        end
+
+        it 'does not serialize diffs' do
+          expect_next_instance_of(PaginatedDiffSerializer) do |instance|
+            expect(instance).not_to receive(:represent)
+          end
+
+          subject
+        end
+
+        context 'with the different pagination option' do
+          subject { go(page: 5, per_page: 5) }
+
+          it_behaves_like 'serializes diffs with expected arguments' do
+            let(:collection) { Gitlab::Diff::FileCollection::MergeRequestDiffBatch }
+            let(:expected_options) { collection_arguments(total_pages: 20) }
+          end
+        end
+
+        context 'with the different diff_view' do
+          subject { go(page: 0, per_page: 5, view: :parallel) }
+
+          it_behaves_like 'serializes diffs with expected arguments' do
+            let(:collection) { Gitlab::Diff::FileCollection::MergeRequestDiffBatch }
+            let(:expected_options) { collection_arguments(total_pages: 20).merge(diff_view: :parallel) }
+          end
+        end
+
+        context 'with the different expanded option' do
+          subject { go(page: 0, per_page: 5, expanded: true ) }
+
+          it_behaves_like 'serializes diffs with expected arguments' do
+            let(:collection) { Gitlab::Diff::FileCollection::MergeRequestDiffBatch }
+            let(:expected_options) { collection_arguments(total_pages: 20) }
+          end
+        end
+
+        context 'with the different ignore_whitespace_change option' do
+          subject { go(page: 0, per_page: 5, w: 1) }
+
+          it_behaves_like 'serializes diffs with expected arguments' do
+            let(:collection) { Gitlab::Diff::FileCollection::Compare }
+            let(:expected_options) { collection_arguments(total_pages: 20) }
+          end
+        end
+      end
+
+      context 'when the paths is given' do
+        subject { go(page: 0, per_page: 5, paths: %w[README CHANGELOG]) }
+
+        it 'does not use cache' do
+          expect(Rails.cache).not_to receive(:fetch).with(/cache:gitlab:PaginatedDiffSerializer/).and_call_original
+
+          subject
+        end
+      end
+    end
+  end
+end
diff --git a/spec/requests/projects/merge_requests_discussions_spec.rb b/spec/requests/projects/merge_requests_discussions_spec.rb
index 4bab1c24169..595222a9eb2 100644
--- a/spec/requests/projects/merge_requests_discussions_spec.rb
+++ b/spec/requests/projects/merge_requests_discussions_spec.rb
@@ -158,6 +158,29 @@ RSpec.describe 'merge requests discussions' do
         end
       end
 
+      context 'when the diff note position changes' do
+        before do
+          # This replicates a position change wherein timestamps aren't updated
+          # which is why `Gitlab::Timeless.timeless` is utilized. This is the
+          # same approach being used in Discussions::UpdateDiffPositionService
+          # which is responsible for updating the positions of diff discussions
+          # when MR updates.
+          first_note.position = Gitlab::Diff::Position.new(
+            old_path: first_note.position.old_path,
+            new_path: first_note.position.new_path,
+            old_line: first_note.position.old_line,
+            new_line: first_note.position.new_line + 1,
+            diff_refs: first_note.position.diff_refs
+          )
+
+          Gitlab::Timeless.timeless(first_note, &:save)
+        end
+
+        it_behaves_like 'cache miss' do
+          let(:changed_notes) { [first_note, second_note] }
+        end
+      end
+
       context 'when merge_request_discussion_cache is disabled' do
         before do
           stub_feature_flags(merge_request_discussion_cache: false)
diff --git a/spec/services/merge_requests/rebase_service_spec.rb b/spec/services/merge_requests/rebase_service_spec.rb
index a46f3cf6148..ca561376581 100644
--- a/spec/services/merge_requests/rebase_service_spec.rb
+++ b/spec/services/merge_requests/rebase_service_spec.rb
@@ -25,30 +25,6 @@ RSpec.describe MergeRequests::RebaseService do
   end
 
   describe '#execute' do
-    context 'when another rebase is already in progress' do
-      before do
-        allow(repository).to receive(:rebase_in_progress?).with(merge_request.id).and_return(true)
-      end
-
-      it 'saves the error message' do
-        service.execute(merge_request)
-
-        expect(merge_request.reload.merge_error).to eq 'Rebase task canceled: Another rebase is already in progress'
-      end
-
-      it 'returns an error' do
-        expect(service.execute(merge_request)).to match(status: :error,
-                                                        message: described_class::REBASE_ERROR)
-      end
-
-      it 'clears rebase_jid' do
-        expect { service.execute(merge_request) }
-          .to change { merge_request.rebase_jid }
-          .from(rebase_jid)
-          .to(nil)
-      end
-    end
-
     shared_examples 'sequence of failure and success' do
       it 'properly clears the error message' do
         allow(repository).to receive(:gitaly_operation_client).and_raise('Something went wrong')
@@ -150,6 +126,13 @@ RSpec.describe MergeRequests::RebaseService do
 
       it_behaves_like 'a service that can execute a successful rebase'
 
+      it 'clears rebase_jid' do
+        expect { service.execute(merge_request) }
+          .to change(merge_request, :rebase_jid)
+          .from(rebase_jid)
+          .to(nil)
+      end
+
       context 'when skip_ci flag is set' do
         let(:skip_ci) { true }
 
diff --git a/spec/support/shared_contexts/features/integrations/integrations_shared_context.rb b/spec/support/shared_contexts/features/integrations/integrations_shared_context.rb
index 66f9d5f6c33..3d2b0433b21 100644
--- a/spec/support/shared_contexts/features/integrations/integrations_shared_context.rb
+++ b/spec/support/shared_contexts/features/integrations/integrations_shared_context.rb
@@ -1,38 +1,38 @@
 # frozen_string_literal: true
 
-Integration.available_integration_names.each do |service|
-  RSpec.shared_context service do
-    include JiraServiceHelper if service == 'jira'
+Integration.available_integration_names.each do |integration|
+  RSpec.shared_context integration do
+    include JiraServiceHelper if integration == 'jira'
 
-    let(:dashed_service) { service.dasherize }
-    let(:service_method) { Project.integration_association_name(service) }
-    let(:service_klass) { Integration.integration_name_to_model(service) }
-    let(:service_instance) { service_klass.new }
-    let(:service_fields) { service_instance.fields }
-    let(:service_attrs_list) { service_fields.inject([]) {|arr, hash| arr << hash[:name].to_sym } }
-    let(:service_attrs) do
-      service_attrs_list.inject({}) do |hash, k|
+    let(:dashed_integration) { integration.dasherize }
+    let(:integration_method) { Project.integration_association_name(integration) }
+    let(:integration_klass) { Integration.integration_name_to_model(integration) }
+    let(:integration_instance) { integration_klass.new }
+    let(:integration_fields) { integration_instance.fields }
+    let(:integration_attrs_list) { integration_fields.inject([]) {|arr, hash| arr << hash[:name].to_sym } }
+    let(:integration_attrs) do
+      integration_attrs_list.inject({}) do |hash, k|
         if k =~ /^(token*|.*_token|.*_key)/
           hash.merge!(k => 'secrettoken')
-        elsif service == 'confluence' && k == :confluence_url
+        elsif integration == 'confluence' && k == :confluence_url
           hash.merge!(k => 'https://example.atlassian.net/wiki')
-        elsif service == 'datadog' && k == :datadog_site
+        elsif integration == 'datadog' && k == :datadog_site
           hash.merge!(k => 'datadoghq.com')
-        elsif service == 'packagist' && k == :server
+        elsif integration == 'packagist' && k == :server
           hash.merge!(k => 'https://packagist.example.com')
         elsif k =~ /^(.*_url|url|webhook)/
           hash.merge!(k => "http://example.com")
-        elsif service_klass.method_defined?("#{k}?")
+        elsif integration_klass.method_defined?("#{k}?")
           hash.merge!(k => true)
-        elsif service == 'irker' && k == :recipients
+        elsif integration == 'irker' && k == :recipients
           hash.merge!(k => 'irc://irc.network.net:666/#channel')
-        elsif service == 'irker' && k == :server_port
+        elsif integration == 'irker' && k == :server_port
           hash.merge!(k => 1234)
-        elsif service == 'jira' && k == :jira_issue_transition_id
+        elsif integration == 'jira' && k == :jira_issue_transition_id
           hash.merge!(k => '1,2,3')
-        elsif service == 'emails_on_push' && k == :recipients
+        elsif integration == 'emails_on_push' && k == :recipients
           hash.merge!(k => 'foo@bar.com')
-        elsif service == 'slack' || service == 'mattermost' && k == :labels_to_be_notified_behavior
+        elsif integration == 'slack' || integration == 'mattermost' && k == :labels_to_be_notified_behavior
           hash.merge!(k => "match_any")
         else
           hash.merge!(k => "someword")
@@ -47,24 +47,24 @@ Integration.available_integration_names.each do |service|
     end
 
     before do
-      enable_license_for_service(service)
-      stub_jira_integration_test if service == 'jira'
+      enable_license_for_integration(integration)
+      stub_jira_integration_test if integration == 'jira'
     end
 
     def initialize_integration(integration, attrs = {})
       record = project.find_or_initialize_integration(integration)
       record.attributes = attrs
-      record.properties = service_attrs
+      record.properties = integration_attrs
       record.save!
       record
     end
 
     private
 
-    def enable_license_for_service(service)
+    def enable_license_for_integration(integration)
       return unless respond_to?(:stub_licensed_features)
 
-      licensed_feature = licensed_features[service]
+      licensed_feature = licensed_features[integration]
       return unless licensed_feature
 
       stub_licensed_features(licensed_feature => true)
diff --git a/spec/support/shared_examples/lib/gitlab/cycle_analytics/event_shared_examples.rb b/spec/support/shared_examples/lib/gitlab/cycle_analytics/event_shared_examples.rb
index 7d341d79bae..6e12b5a0e85 100644
--- a/spec/support/shared_examples/lib/gitlab/cycle_analytics/event_shared_examples.rb
+++ b/spec/support/shared_examples/lib/gitlab/cycle_analytics/event_shared_examples.rb
@@ -3,6 +3,7 @@
 RSpec.shared_examples_for 'value stream analytics event' do
   let(:params) { {} }
   let(:instance) { described_class.new(params) }
+  let(:expected_hash_code) { Digest::SHA256.hexdigest(instance.class.identifier.to_s) }
 
   it { expect(described_class.name).to be_a_kind_of(String) }
   it { expect(described_class.identifier).to be_a_kind_of(Symbol) }
@@ -19,4 +20,16 @@ RSpec.shared_examples_for 'value stream analytics event' do
       expect(output_query).to be_a_kind_of(ActiveRecord::Relation)
     end
   end
+
+  describe '#hash_code' do
+    it 'returns a hash that uniquely identifies an event' do
+      expect(instance.hash_code).to eq(expected_hash_code)
+    end
+
+    it 'does not differ when the same object is built with the same params' do
+      another_instance_with_same_params = described_class.new(params)
+
+      expect(another_instance_with_same_params.hash_code).to eq(instance.hash_code)
+    end
+  end
 end
diff --git a/spec/support/shared_examples/models/cycle_analytics_stage_shared_examples.rb b/spec/support/shared_examples/models/cycle_analytics_stage_shared_examples.rb
index d23f95b2e9e..cf38a583944 100644
--- a/spec/support/shared_examples/models/cycle_analytics_stage_shared_examples.rb
+++ b/spec/support/shared_examples/models/cycle_analytics_stage_shared_examples.rb
@@ -122,6 +122,22 @@ RSpec.shared_examples 'value stream analytics stage' do
       expect(stage.parent_id).to eq(parent.id)
     end
   end
+
+  describe '#hash_code' do
+    it 'does not differ when the same object is built with the same params' do
+      stage_1 = build(factory)
+      stage_2 = build(factory)
+
+      expect(stage_1.events_hash_code).to eq(stage_2.events_hash_code)
+    end
+
+    it 'differs when the stage events are different' do
+      stage_1 = build(factory, start_event_identifier: :merge_request_created, end_event_identifier: :merge_request_merged)
+      stage_2 = build(factory, start_event_identifier: :issue_created, end_event_identifier: :issue_first_mentioned_in_commit)
+
+      expect(stage_1.events_hash_code).not_to eq(stage_2.events_hash_code)
+    end
+  end
 end
 
 RSpec.shared_examples 'value stream analytics label based stage' do