From a9f214d42107c847fcc8fb2a5dff78ba17363e41 Mon Sep 17 00:00:00 2001
From: GitLab Bot <gitlab-bot@gitlab.com>
Date: Tue, 31 May 2022 06:09:17 +0000
Subject: [PATCH] Add latest changes from gitlab-org/gitlab@master

---
 .../list/components/issues_list_app.vue       | 17 ++++++---
 .../javascripts/issues/list/constants.js      |  4 ++
 app/assets/javascripts/issues/list/index.js   |  4 ++
 app/helpers/issues_helper.rb                  |  4 +-
 app/serializers/diff_file_entity.rb           | 12 +++++-
 app/services/auto_merge/base_service.rb       |  5 ++-
 ...ll_integrations_enable_ssl_verification.rb | 15 ++++++++
 ...ll_integrations_enable_ssl_verification.rb | 18 +++++++++
 db/schema_migrations/20220525131557           |  1 +
 db/schema_migrations/20220525131624           |  1 +
 db/structure.sql                              |  2 -
 doc/administration/audit_event_streaming.md   | 22 ++++++++---
 locale/gitlab.pot                             |  3 ++
 .../create_merge_request_spec.rb              |  5 ++-
 .../list/components/issues_list_app_spec.js   | 37 +++++++++++++++++--
 spec/helpers/issues_helper_spec.rb            |  2 +
 ...tegrations_enable_ssl_verification_spec.rb | 35 ++++++++++++++++++
 spec/serializers/diff_file_entity_spec.rb     | 33 +++++++++++++++++
 18 files changed, 198 insertions(+), 22 deletions(-)
 create mode 100644 db/post_migrate/20220525131557_cleanup_backfill_integrations_enable_ssl_verification.rb
 create mode 100644 db/post_migrate/20220525131624_drop_temporary_index_for_backfill_integrations_enable_ssl_verification.rb
 create mode 100644 db/schema_migrations/20220525131557
 create mode 100644 db/schema_migrations/20220525131624
 create mode 100644 spec/migrations/cleanup_backfill_integrations_enable_ssl_verification_spec.rb

diff --git a/app/assets/javascripts/issues/list/components/issues_list_app.vue b/app/assets/javascripts/issues/list/components/issues_list_app.vue
index e5c557ce769..4e5d0c9ac57 100644
--- a/app/assets/javascripts/issues/list/components/issues_list_app.vue
+++ b/app/assets/javascripts/issues/list/components/issues_list_app.vue
@@ -117,6 +117,7 @@ export default {
     'autocompleteAwardEmojisPath',
     'calendarPath',
     'canBulkUpdate',
+    'canCreateProjects',
     'canReadCrmContact',
     'canReadCrmOrganization',
     'emptyStateSvgPath',
@@ -136,6 +137,7 @@ export default {
     'isSignedIn',
     'jiraIntegrationPath',
     'newIssuePath',
+    'newProjectPath',
     'releasesPath',
     'rssPath',
     'showNewIssueLink',
@@ -844,12 +846,17 @@ export default {
     </issuable-list>
 
     <template v-else-if="isSignedIn">
-      <gl-empty-state
-        :description="$options.i18n.noIssuesSignedInDescription"
-        :title="$options.i18n.noIssuesSignedInTitle"
-        :svg-path="emptyStateSvgPath"
-      >
+      <gl-empty-state :title="$options.i18n.noIssuesSignedInTitle" :svg-path="emptyStateSvgPath">
+        <template #description>
+          <p>{{ $options.i18n.noIssuesSignedInDescription }}</p>
+          <p v-if="canCreateProjects">
+            <strong>{{ $options.i18n.noGroupIssuesSignedInDescription }}</strong>
+          </p>
+        </template>
         <template #actions>
+          <gl-button v-if="canCreateProjects" :href="newProjectPath" variant="confirm">
+            {{ $options.i18n.newProjectLabel }}
+          </gl-button>
           <gl-button v-if="showNewIssueLink" :href="newIssuePath" variant="confirm">
             {{ $options.i18n.newIssueLabel }}
           </gl-button>
diff --git a/app/assets/javascripts/issues/list/constants.js b/app/assets/javascripts/issues/list/constants.js
index c7098d048ad..74f801f685c 100644
--- a/app/assets/javascripts/issues/list/constants.js
+++ b/app/assets/javascripts/issues/list/constants.js
@@ -29,7 +29,11 @@ export const i18n = {
   jiraIntegrationSecondaryMessage: s__('JiraService|This feature requires a Premium plan.'),
   jiraIntegrationTitle: s__('JiraService|Using Jira for issue tracking?'),
   newIssueLabel: __('New issue'),
+  newProjectLabel: __('New project'),
   noClosedIssuesTitle: __('There are no closed issues'),
+  noGroupIssuesSignedInDescription: __(
+    'Issues exist in projects, so to create an issue, first create a project.',
+  ),
   noOpenIssuesDescription: __('To keep this project going, create a new issue'),
   noOpenIssuesTitle: __('There are no open issues'),
   noIssuesSignedInDescription: __(
diff --git a/app/assets/javascripts/issues/list/index.js b/app/assets/javascripts/issues/list/index.js
index 7cfd8badf48..c89a6385bc4 100644
--- a/app/assets/javascripts/issues/list/index.js
+++ b/app/assets/javascripts/issues/list/index.js
@@ -80,6 +80,7 @@ export function mountIssuesListApp() {
     autocompleteAwardEmojisPath,
     calendarPath,
     canBulkUpdate,
+    canCreateProjects,
     canEdit,
     canImportIssues,
     canReadCrmContact,
@@ -109,6 +110,7 @@ export function mountIssuesListApp() {
     markdownHelpPath,
     maxAttachmentSize,
     newIssuePath,
+    newProjectPath,
     projectImportJiraPath,
     quickActionsHelpPath,
     releasesPath,
@@ -133,6 +135,7 @@ export function mountIssuesListApp() {
       autocompleteAwardEmojisPath,
       calendarPath,
       canBulkUpdate: parseBoolean(canBulkUpdate),
+      canCreateProjects: parseBoolean(canCreateProjects),
       canReadCrmContact: parseBoolean(canReadCrmContact),
       canReadCrmOrganization: parseBoolean(canReadCrmOrganization),
       emptyStateSvgPath,
@@ -153,6 +156,7 @@ export function mountIssuesListApp() {
       isSignedIn: parseBoolean(isSignedIn),
       jiraIntegrationPath,
       newIssuePath,
+      newProjectPath,
       releasesPath,
       rssPath,
       showNewIssueLink: parseBoolean(showNewIssueLink),
diff --git a/app/helpers/issues_helper.rb b/app/helpers/issues_helper.rb
index 98afab554d2..bf0fa2c3e77 100644
--- a/app/helpers/issues_helper.rb
+++ b/app/helpers/issues_helper.rb
@@ -238,10 +238,12 @@ module IssuesHelper
 
   def group_issues_list_data(group, current_user)
     common_issues_list_data(group, current_user).merge(
+      can_create_projects: can?(current_user, :create_projects, group).to_s,
       can_read_crm_contact: can?(current_user, :read_crm_contact, group).to_s,
       can_read_crm_organization: can?(current_user, :read_crm_organization, group).to_s,
       has_any_issues: @has_issues.to_s,
-      has_any_projects: @has_projects.to_s
+      has_any_projects: @has_projects.to_s,
+      new_project_path: new_project_path(namespace_id: group.id)
     )
   end
 
diff --git a/app/serializers/diff_file_entity.rb b/app/serializers/diff_file_entity.rb
index ef856ee0116..9f8628fe849 100644
--- a/app/serializers/diff_file_entity.rb
+++ b/app/serializers/diff_file_entity.rb
@@ -56,8 +56,7 @@ class DiffFileEntity < DiffFileBaseEntity
 
   # Used for inline diffs
   expose :highlighted_diff_lines, using: DiffLineEntity, if: -> (diff_file, options) { inline_diff_view?(options) && diff_file.text? } do |diff_file|
-    file = conflict_file(options, diff_file) || diff_file
-    file.diff_lines_for_serializer
+    highlighted_diff_lines_for(diff_file, options)
   end
 
   expose :is_fully_expanded do |diff_file|
@@ -89,6 +88,15 @@ class DiffFileEntity < DiffFileBaseEntity
     # If nothing is present, inline will be the default.
     options.fetch(:diff_view, :inline).to_sym
   end
+
+  def highlighted_diff_lines_for(diff_file, options)
+    file = conflict_file(options, diff_file) || diff_file
+
+    file.diff_lines_for_serializer
+  rescue Gitlab::Git::Conflict::Parser::UnmergeableFile
+    # Fallback to diff_file as it means that conflict lines can't be parsed due to limit
+    diff_file.diff_lines_for_serializer
+  end
 end
 
 DiffFileEntity.prepend_mod
diff --git a/app/services/auto_merge/base_service.rb b/app/services/auto_merge/base_service.rb
index 4ed4368d3b7..2a32f0c74ac 100644
--- a/app/services/auto_merge/base_service.rb
+++ b/app/services/auto_merge/base_service.rb
@@ -55,7 +55,10 @@ module AutoMerge
     def available_for?(merge_request)
       strong_memoize("available_for_#{merge_request.id}") do
         merge_request.can_be_merged_by?(current_user) &&
-          merge_request.mergeable_state?(skip_ci_check: true) &&
+          merge_request.open? &&
+          !merge_request.broken? &&
+          !merge_request.draft? &&
+          merge_request.mergeable_discussions_state? &&
           yield
       end
     end
diff --git a/db/post_migrate/20220525131557_cleanup_backfill_integrations_enable_ssl_verification.rb b/db/post_migrate/20220525131557_cleanup_backfill_integrations_enable_ssl_verification.rb
new file mode 100644
index 00000000000..3bd4b21c6fd
--- /dev/null
+++ b/db/post_migrate/20220525131557_cleanup_backfill_integrations_enable_ssl_verification.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class CleanupBackfillIntegrationsEnableSslVerification < Gitlab::Database::Migration[2.0]
+  disable_ddl_transaction!
+
+  MIGRATION = 'BackfillIntegrationsEnableSslVerification'
+
+  def up
+    finalize_background_migration(MIGRATION)
+  end
+
+  def down
+    # no-op
+  end
+end
diff --git a/db/post_migrate/20220525131624_drop_temporary_index_for_backfill_integrations_enable_ssl_verification.rb b/db/post_migrate/20220525131624_drop_temporary_index_for_backfill_integrations_enable_ssl_verification.rb
new file mode 100644
index 00000000000..95abac4b7ac
--- /dev/null
+++ b/db/post_migrate/20220525131624_drop_temporary_index_for_backfill_integrations_enable_ssl_verification.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class DropTemporaryIndexForBackfillIntegrationsEnableSslVerification < Gitlab::Database::Migration[2.0]
+  disable_ddl_transaction!
+
+  INDEX_NAME = 'tmp_index_integrations_on_id_where_type_droneci_or_teamcity'
+  INDEX_CONDITION = "type_new IN ('Integrations::DroneCi', 'Integrations::Teamcity') " \
+    "AND encrypted_properties IS NOT NULL"
+
+  def up
+    remove_concurrent_index_by_name :integrations, INDEX_NAME
+  end
+
+  def down
+    # this index is used in 20220209121435_backfill_integrations_enable_ssl_verification
+    add_concurrent_index :integrations, :id, where: INDEX_CONDITION, name: INDEX_NAME
+  end
+end
diff --git a/db/schema_migrations/20220525131557 b/db/schema_migrations/20220525131557
new file mode 100644
index 00000000000..c1b29410ef0
--- /dev/null
+++ b/db/schema_migrations/20220525131557
@@ -0,0 +1 @@
+fe0e9acc39c2408853ea3fc35574c553172ad381a5b6f243578f44ed77dc75f8
\ No newline at end of file
diff --git a/db/schema_migrations/20220525131624 b/db/schema_migrations/20220525131624
new file mode 100644
index 00000000000..71a3d6d26d2
--- /dev/null
+++ b/db/schema_migrations/20220525131624
@@ -0,0 +1 @@
+f34c6e7b75d375342f5c88a9c7b98e15031a6dcdadf7e7dad862ef5f32a54e68
\ No newline at end of file
diff --git a/db/structure.sql b/db/structure.sql
index d610885ba57..f72dc4d0593 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -29975,8 +29975,6 @@ CREATE INDEX tmp_index_for_null_project_namespace_id ON projects USING btree (id
 
 CREATE INDEX tmp_index_for_project_namespace_id_migration_on_routes ON routes USING btree (id) WHERE ((namespace_id IS NULL) AND ((source_type)::text = 'Project'::text));
 
-CREATE INDEX tmp_index_integrations_on_id_where_type_droneci_or_teamcity ON integrations USING btree (id) WHERE ((type_new = ANY (ARRAY['Integrations::DroneCi'::text, 'Integrations::Teamcity'::text])) AND (encrypted_properties IS NOT NULL));
-
 CREATE INDEX tmp_index_issues_on_issue_type_and_id ON issues USING btree (issue_type, id);
 
 CREATE INDEX tmp_index_members_on_state ON members USING btree (state) WHERE (state = 2);
diff --git a/doc/administration/audit_event_streaming.md b/doc/administration/audit_event_streaming.md
index 457820c75df..0f4b3b31e8a 100644
--- a/doc/administration/audit_event_streaming.md
+++ b/doc/administration/audit_event_streaming.md
@@ -175,6 +175,8 @@ To configure streaming audit events for Git operations, see [Add a new event str
 
 ### Headers
 
+> `X-Gitlab-Audit-Event-Type` [introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/86881) in GitLab 15.0.
+
 Headers are formatted as follows:
 
 ```plaintext
@@ -182,6 +184,7 @@ POST /logs HTTP/1.1
 Host: <DESTINATION_HOST>
 Content-Type: application/x-www-form-urlencoded
 X-Gitlab-Event-Streaming-Token: <DESTINATION_TOKEN>
+X-Gitlab-Audit-Event-Type: repository_git_operation
 ```
 
 ### Example payloads for SSH events
@@ -212,7 +215,8 @@ Fetch:
   "target_details": "example-project",
   "created_at": "2022-02-23T06:21:05.283Z",
   "target_type": "Project",
-  "target_id": 29
+  "target_id": 29,
+  "event_type": "repository_git_operation"
 }
 ```
 
@@ -242,7 +246,8 @@ Push:
   "target_details": "example-project",
   "created_at": "2022-02-23T06:23:08.746Z",
   "target_type": "Project",
-  "target_id": 29
+  "target_id": 29,
+  "event_type": "repository_git_operation"
 }
 ```
 
@@ -274,7 +279,8 @@ Fetch:
   "target_details": "example-project",
   "created_at": "2022-02-23T06:25:43.938Z",
   "target_type": "Project",
-  "target_id": 29
+  "target_id": 29,
+  "event_type": "repository_git_operation"
 }
 ```
 
@@ -304,7 +310,8 @@ Push:
   "target_details": "example-project",
   "created_at": "2022-02-23T06:26:29.294Z",
   "target_type": "Project",
-  "target_id": 29
+  "target_id": 29,
+  "event_type": "repository_git_operation"
 }
 ```
 
@@ -333,7 +340,8 @@ Fetch:
   "target_details": "example-group/example-project",
   "created_at": "2022-02-23T06:27:17.873Z",
   "target_type": "Project",
-  "target_id": 29
+  "target_id": 29,
+  "event_type": "repository_git_operation"
 }
 ```
 
@@ -352,6 +360,7 @@ POST /logs HTTP/1.1
 Host: <DESTINATION_HOST>
 Content-Type: application/x-www-form-urlencoded
 X-Gitlab-Event-Streaming-Token: <DESTINATION_TOKEN>
+X-Gitlab-Audit-Event-Type: audit_operation
 ```
 
 ### Example payload
@@ -377,6 +386,7 @@ X-Gitlab-Event-Streaming-Token: <DESTINATION_TOKEN>
   "target_details": "merge request title",
   "created_at": "2022-03-09T06:53:11.181Z",
   "target_type": "MergeRequest",
-  "target_id": 20
+  "target_id": 20,
+  "event_type": "audit_operation"
 }
 ```
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 2fe2430c42f..e190a867668 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -21324,6 +21324,9 @@ msgstr ""
 msgid "Issues closed"
 msgstr ""
 
+msgid "Issues exist in projects, so to create an issue, first create a project."
+msgstr ""
+
 msgid "Issues must match this scope to appear in this list."
 msgstr ""
 
diff --git a/qa/qa/specs/features/browser_ui/3_create/merge_request/create_merge_request_spec.rb b/qa/qa/specs/features/browser_ui/3_create/merge_request/create_merge_request_spec.rb
index f4ed9f28dac..2beea45a81d 100644
--- a/qa/qa/specs/features/browser_ui/3_create/merge_request/create_merge_request_spec.rb
+++ b/qa/qa/specs/features/browser_ui/3_create/merge_request/create_merge_request_spec.rb
@@ -1,7 +1,10 @@
 # frozen_string_literal: true
 
 module QA
-  RSpec.describe 'Create' do
+  RSpec.describe 'Create', quarantine: {
+    issue: 'https://gitlab.com/gitlab-org/gitlab/-/issues/363807',
+    type: :stale
+  } do
     describe 'Create a new merge request' do
       let(:project) do
         Resource::Project.fabricate_via_api! do |project|
diff --git a/spec/frontend/issues/list/components/issues_list_app_spec.js b/spec/frontend/issues/list/components/issues_list_app_spec.js
index 14aac5ea562..934178cda0e 100644
--- a/spec/frontend/issues/list/components/issues_list_app_spec.js
+++ b/spec/frontend/issues/list/components/issues_list_app_spec.js
@@ -67,6 +67,7 @@ describe('CE IssuesListApp component', () => {
     autocompleteAwardEmojisPath: 'autocomplete/award/emojis/path',
     calendarPath: 'calendar/path',
     canBulkUpdate: false,
+    canCreateProjects: false,
     canReadCrmContact: false,
     canReadCrmOrganization: false,
     emptyStateSvgPath: 'empty-state.svg',
@@ -88,6 +89,7 @@ describe('CE IssuesListApp component', () => {
     isSignedIn: true,
     jiraIntegrationPath: 'jira/integration/path',
     newIssuePath: 'new/issue/path',
+    newProjectPath: 'new/project/path',
     releasesPath: 'releases/path',
     rssPath: 'rss/path',
     showNewIssueLink: true,
@@ -118,6 +120,7 @@ describe('CE IssuesListApp component', () => {
     issuesQueryResponse = jest.fn().mockResolvedValue(defaultQueryResponse),
     issuesCountsQueryResponse = jest.fn().mockResolvedValue(getIssuesCountsQueryResponse),
     sortPreferenceMutationResponse = jest.fn().mockResolvedValue(setSortPreferenceMutationResponse),
+    stubs = {},
     mountFn = shallowMount,
   } = {}) => {
     const requestHandlers = [
@@ -136,6 +139,7 @@ describe('CE IssuesListApp component', () => {
       data() {
         return data;
       },
+      stubs,
     });
   };
 
@@ -521,10 +525,12 @@ describe('CE IssuesListApp component', () => {
 
         it('shows empty state', () => {
           expect(findGlEmptyState().props()).toMatchObject({
-            description: IssuesListApp.i18n.noIssuesSignedInDescription,
             title: IssuesListApp.i18n.noIssuesSignedInTitle,
             svgPath: defaultProvide.emptyStateSvgPath,
           });
+          expect(findGlEmptyState().text()).toContain(
+            IssuesListApp.i18n.noIssuesSignedInDescription,
+          );
         });
 
         it('shows "New issue" and import/export buttons', () => {
@@ -538,11 +544,11 @@ describe('CE IssuesListApp component', () => {
 
         it('shows Jira integration information', () => {
           const paragraphs = wrapper.findAll('p');
-          expect(paragraphs.at(1).text()).toContain(IssuesListApp.i18n.jiraIntegrationTitle);
-          expect(paragraphs.at(2).text()).toContain(
+          expect(paragraphs.at(2).text()).toContain(IssuesListApp.i18n.jiraIntegrationTitle);
+          expect(paragraphs.at(3).text()).toContain(
             'Enable the Jira integration to view your Jira issues in GitLab.',
           );
-          expect(paragraphs.at(3).text()).toContain(
+          expect(paragraphs.at(4).text()).toContain(
             IssuesListApp.i18n.jiraIntegrationSecondaryMessage,
           );
           expect(findGlLink().text()).toBe('Enable the Jira integration');
@@ -550,6 +556,29 @@ describe('CE IssuesListApp component', () => {
         });
       });
 
+      describe('when user is logged in and can create projects', () => {
+        beforeEach(() => {
+          wrapper = mountComponent({
+            provide: { canCreateProjects: true, hasAnyIssues: false, isSignedIn: true },
+            stubs: { GlEmptyState },
+          });
+        });
+
+        it('shows empty state with additional description about creating projects', () => {
+          expect(findGlEmptyState().text()).toContain(
+            IssuesListApp.i18n.noIssuesSignedInDescription,
+          );
+          expect(findGlEmptyState().text()).toContain(
+            IssuesListApp.i18n.noGroupIssuesSignedInDescription,
+          );
+        });
+
+        it('shows "New project" button', () => {
+          expect(findGlButton().text()).toBe(IssuesListApp.i18n.newProjectLabel);
+          expect(findGlButton().attributes('href')).toBe(defaultProvide.newProjectPath);
+        });
+      });
+
       describe('when user is logged out', () => {
         beforeEach(() => {
           wrapper = mountComponent({
diff --git a/spec/helpers/issues_helper_spec.rb b/spec/helpers/issues_helper_spec.rb
index dd5e162b444..64d596595bb 100644
--- a/spec/helpers/issues_helper_spec.rb
+++ b/spec/helpers/issues_helper_spec.rb
@@ -355,12 +355,14 @@ RSpec.describe IssuesHelper do
       expected = {
         autocomplete_award_emojis_path: autocomplete_award_emojis_path,
         calendar_path: '#',
+        can_create_projects: 'true',
         empty_state_svg_path: '#',
         full_path: group.full_path,
         has_any_issues: false.to_s,
         has_any_projects: true.to_s,
         is_signed_in: current_user.present?.to_s,
         jira_integration_path: help_page_url('integration/jira/issues', anchor: 'view-jira-issues'),
+        new_project_path: new_project_path(namespace_id: group.id),
         rss_path: '#',
         sign_in_path: new_user_session_path
       }
diff --git a/spec/migrations/cleanup_backfill_integrations_enable_ssl_verification_spec.rb b/spec/migrations/cleanup_backfill_integrations_enable_ssl_verification_spec.rb
new file mode 100644
index 00000000000..1517405b358
--- /dev/null
+++ b/spec/migrations/cleanup_backfill_integrations_enable_ssl_verification_spec.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe CleanupBackfillIntegrationsEnableSslVerification, :migration do
+  let(:job_class_name) { 'BackfillIntegrationsEnableSslVerification' }
+
+  before do
+    # Jobs enqueued in Sidekiq.
+    Sidekiq::Testing.disable! do
+      BackgroundMigrationWorker.perform_in(10, job_class_name, [1, 2])
+      BackgroundMigrationWorker.perform_in(20, job_class_name, [3, 4])
+    end
+
+    # Jobs tracked in the database.
+    Gitlab::Database::BackgroundMigrationJob.create!(
+      class_name: job_class_name,
+      arguments: [5, 6],
+      status: Gitlab::Database::BackgroundMigrationJob.statuses['pending']
+    )
+    Gitlab::Database::BackgroundMigrationJob.create!(
+      class_name: job_class_name,
+      arguments: [7, 8],
+      status: Gitlab::Database::BackgroundMigrationJob.statuses['succeeded']
+    )
+
+    migrate!
+  end
+
+  it_behaves_like(
+    'finalized tracked background migration',
+    Gitlab::BackgroundMigration::BackfillIntegrationsEnableSslVerification
+  )
+end
diff --git a/spec/serializers/diff_file_entity_spec.rb b/spec/serializers/diff_file_entity_spec.rb
index ebfb21c4311..48099cb1fdf 100644
--- a/spec/serializers/diff_file_entity_spec.rb
+++ b/spec/serializers/diff_file_entity_spec.rb
@@ -91,5 +91,38 @@ RSpec.describe DiffFileEntity do
     end
   end
 
+  describe '#highlighted_diff_lines' do
+    context 'file without a conflict' do
+      let(:options) { { conflicts: {} } }
+
+      it 'calls diff_lines_for_serializer on diff_file' do
+        # #diff_lines_for_serializer gets called in #fully_expanded? as well so we expect twice
+        expect(diff_file).to receive(:diff_lines_for_serializer).twice.and_return([])
+        expect(subject[:highlighted_diff_lines]).to eq([])
+      end
+    end
+
+    context 'file with a conflict' do
+      let(:conflict_file) { instance_double(Gitlab::Conflict::File, conflict_type: :both_modified) }
+      let(:options) { { conflicts: { diff_file.new_path => conflict_file } } }
+
+      it 'calls diff_lines_for_serializer on matching conflict file' do
+        expect(conflict_file).to receive(:diff_lines_for_serializer).and_return([])
+        expect(subject[:highlighted_diff_lines]).to eq([])
+      end
+
+      context 'when Gitlab::Git::Conflict::Parser::UnmergeableFile gets raised' do
+        before do
+          allow(conflict_file).to receive(:diff_lines_for_serializer).and_raise(Gitlab::Git::Conflict::Parser::UnmergeableFile)
+        end
+
+        it 'falls back to diff_file diff_lines_for_serializer' do
+          expect(diff_file).to receive(:diff_lines_for_serializer).and_return([])
+          expect(subject[:highlighted_diff_lines]).to eq([])
+        end
+      end
+    end
+  end
+
   it_behaves_like 'diff file with conflict_type'
 end