From 4fed8ce9c8b17c1afa3b26ff0648c5e159f51f5f Mon Sep 17 00:00:00 2001
From: GitLab Bot <gitlab-bot@gitlab.com>
Date: Tue, 22 Dec 2020 06:10:02 +0000
Subject: [PATCH] Add latest changes from gitlab-org/gitlab@master

---
 Gemfile                                       |  2 +-
 Gemfile.lock                                  | 28 +++----
 .../blob_header_default_actions.vue           |  3 +-
 .../merge_requests/diffs_controller.rb        | 14 ++++
 app/models/clusters/applications/runner.rb    |  2 +-
 .../merge_requests/cleanup_refs_service.rb    |  2 +
 .../settings/_two_factor_auth.html.haml       |  2 +-
 .../247184-instument-file-by-file-mrs.yml     |  5 ++
 .../pb-handle-git-errors-cleanup-refs.yml     |  5 ++
 ...ate-gitlab-runner-helm-chart-to-0-24-0.yml |  5 ++
 .../usage_data_i_code_review_mr_diffs.yml     |  8 ++
 ...ata_i_code_review_mr_single_file_diffs.yml |  8 ++
 ...a_i_code_review_user_single_file_diffs.yml |  8 ++
 db/fixtures/development/03_project.rb         |  1 +
 doc/administration/nfs.md                     |  7 +-
 .../reference_architectures/10k_users.md      |  6 ++
 .../reference_architectures/25k_users.md      |  6 ++
 .../reference_architectures/2k_users.md       |  8 +-
 .../reference_architectures/3k_users.md       |  6 ++
 .../reference_architectures/50k_users.md      |  6 ++
 .../reference_architectures/5k_users.md       |  6 ++
 .../troubleshooting.md                        |  8 +-
 .../known_events/common.yml                   | 15 ++++
 .../merge_request_activity_unique_counter.rb  | 38 ++++++++++
 qa/qa/page/component/snippet.rb               | 42 ++++++++++-
 .../copy_snippet_file_contents_spec.rb        | 75 +++++++++++++++++++
 .../3_create/snippet/share_snippet_spec.rb    |  2 +-
 .../merge_requests/diffs_controller_spec.rb   | 51 +++++++++++++
 .../hll_redis_counter_spec.rb                 |  3 +-
 ...ge_request_activity_unique_counter_spec.rb | 42 +++++++++++
 .../cleanup_refs_service_spec.rb              | 20 +++++
 31 files changed, 403 insertions(+), 31 deletions(-)
 create mode 100644 changelogs/unreleased/247184-instument-file-by-file-mrs.yml
 create mode 100644 changelogs/unreleased/pb-handle-git-errors-cleanup-refs.yml
 create mode 100644 changelogs/unreleased/update-gitlab-runner-helm-chart-to-0-24-0.yml
 create mode 100644 config/feature_flags/development/usage_data_i_code_review_mr_diffs.yml
 create mode 100644 config/feature_flags/development/usage_data_i_code_review_mr_single_file_diffs.yml
 create mode 100644 config/feature_flags/development/usage_data_i_code_review_user_single_file_diffs.yml
 create mode 100644 lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb
 create mode 100644 qa/qa/specs/features/browser_ui/3_create/snippet/copy_snippet_file_contents_spec.rb
 create mode 100644 spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb

diff --git a/Gemfile b/Gemfile
index 49d0841be3c..72b5bc44e30 100644
--- a/Gemfile
+++ b/Gemfile
@@ -360,7 +360,7 @@ group :development, :test do
 
   gem 'database_cleaner', '~> 1.7.0'
   gem 'factory_bot_rails', '~> 5.1.0'
-  gem 'rspec-rails', '~> 4.0.0'
+  gem 'rspec-rails', '~> 4.0.1'
 
   # Prevent occasions where minitest is not bundled in packaged versions of ruby (see #3826)
   gem 'minitest', '~> 5.11.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 1cd90080fd8..f7d4b4dfecb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -252,7 +252,7 @@ GEM
       devise (~> 4.0)
       railties (< 6.1)
       rotp (~> 2.0)
-    diff-lcs (1.3)
+    diff-lcs (1.4.4)
     diff_match_patch (0.1.0)
     diffy (3.3.0)
     discordrb-webhooks-blackst0ne (3.3.0)
@@ -989,25 +989,25 @@ GEM
       chunky_png
     rqrcode-rails3 (0.1.7)
       rqrcode (>= 0.4.2)
-    rspec (3.9.0)
-      rspec-core (~> 3.9.0)
-      rspec-expectations (~> 3.9.0)
-      rspec-mocks (~> 3.9.0)
-    rspec-core (3.9.1)
-      rspec-support (~> 3.9.1)
-    rspec-expectations (3.9.1)
+    rspec (3.10.0)
+      rspec-core (~> 3.10.0)
+      rspec-expectations (~> 3.10.0)
+      rspec-mocks (~> 3.10.0)
+    rspec-core (3.10.0)
+      rspec-support (~> 3.10.0)
+    rspec-expectations (3.10.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.9.0)
-    rspec-mocks (3.9.1)
+      rspec-support (~> 3.10.0)
+    rspec-mocks (3.10.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.9.0)
+      rspec-support (~> 3.10.0)
     rspec-parameterized (0.4.2)
       binding_ninja (>= 0.2.3)
       parser
       proc_to_ast
       rspec (>= 2.13, < 4)
       unparser
-    rspec-rails (4.0.0)
+    rspec-rails (4.0.1)
       actionpack (>= 4.2)
       activesupport (>= 4.2)
       railties (>= 4.2)
@@ -1017,7 +1017,7 @@ GEM
       rspec-support (~> 3.9)
     rspec-retry (0.6.1)
       rspec-core (> 3.3)
-    rspec-support (3.9.2)
+    rspec-support (3.10.0)
     rspec_junit_formatter (0.4.1)
       rspec-core (>= 2, < 4, != 2.12.0)
     rspec_profiling (0.0.6)
@@ -1481,7 +1481,7 @@ DEPENDENCIES
   rouge (~> 3.26.0)
   rqrcode-rails3 (~> 0.1.7)
   rspec-parameterized
-  rspec-rails (~> 4.0.0)
+  rspec-rails (~> 4.0.1)
   rspec-retry (~> 0.6.1)
   rspec_junit_formatter
   rspec_profiling (~> 0.0.6)
diff --git a/app/assets/javascripts/blob/components/blob_header_default_actions.vue b/app/assets/javascripts/blob/components/blob_header_default_actions.vue
index 6eddec31166..cab37df68b4 100644
--- a/app/assets/javascripts/blob/components/blob_header_default_actions.vue
+++ b/app/assets/javascripts/blob/components/blob_header_default_actions.vue
@@ -50,7 +50,7 @@ export default {
 };
 </script>
 <template>
-  <gl-button-group>
+  <gl-button-group data-qa-selector="default_actions_container">
     <gl-button
       v-if="!hasRenderError"
       v-gl-tooltip.hover
@@ -59,6 +59,7 @@ export default {
       :disabled="copyDisabled"
       :data-clipboard-target="getBlobHashTarget"
       data-testid="copyContentsButton"
+      data-qa-selector="copy_contents_button"
       icon="copy-to-clipboard"
       category="primary"
       variant="default"
diff --git a/app/controllers/projects/merge_requests/diffs_controller.rb b/app/controllers/projects/merge_requests/diffs_controller.rb
index da19ddf6105..bcd60674cec 100644
--- a/app/controllers/projects/merge_requests/diffs_controller.rb
+++ b/app/controllers/projects/merge_requests/diffs_controller.rb
@@ -11,6 +11,8 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
 
   around_action :allow_gitaly_ref_name_caching
 
+  after_action :track_viewed_diffs_events, only: [:diffs_batch]
+
   def show
     render_diffs
   end
@@ -188,4 +190,16 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
 
     Discussions::CaptureDiffNotePositionsService.new(@merge_request).execute
   end
+
+  def track_viewed_diffs_events
+    return if request.headers['DNT'] == '1'
+
+    Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter
+      .track_mr_diffs_action(merge_request: @merge_request)
+
+    return unless current_user&.view_diffs_file_by_file
+
+    Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter
+      .track_mr_diffs_single_file_action(merge_request: @merge_request, user: current_user)
+  end
 end
diff --git a/app/models/clusters/applications/runner.rb b/app/models/clusters/applications/runner.rb
index 1e41b6f4f31..56acac53e0b 100644
--- a/app/models/clusters/applications/runner.rb
+++ b/app/models/clusters/applications/runner.rb
@@ -3,7 +3,7 @@
 module Clusters
   module Applications
     class Runner < ApplicationRecord
-      VERSION = '0.23.0'
+      VERSION = '0.24.0'
 
       self.table_name = 'clusters_applications_runners'
 
diff --git a/app/services/merge_requests/cleanup_refs_service.rb b/app/services/merge_requests/cleanup_refs_service.rb
index 23ac8e393f4..2094ea00160 100644
--- a/app/services/merge_requests/cleanup_refs_service.rb
+++ b/app/services/merge_requests/cleanup_refs_service.rb
@@ -36,6 +36,8 @@ module MergeRequests
       return error('Failed to update schedule.') unless update_schedule
 
       success
+    rescue Gitlab::Git::Repository::GitError, Gitlab::Git::CommandError => e
+      error(e.message)
     end
 
     private
diff --git a/app/views/groups/settings/_two_factor_auth.html.haml b/app/views/groups/settings/_two_factor_auth.html.haml
index d2d4c27c826..fac3df5237f 100644
--- a/app/views/groups/settings/_two_factor_auth.html.haml
+++ b/app/views/groups/settings/_two_factor_auth.html.haml
@@ -18,6 +18,6 @@
 - unless group.has_parent?
   .form-group
     .form-check
-      = f.check_box :allow_mfa_for_subgroups, class: 'form-check-input', checked: group.namespace_settings.allow_mfa_for_subgroups
+      = f.check_box :allow_mfa_for_subgroups, class: 'form-check-input', checked: group.namespace_settings&.allow_mfa_for_subgroups
       = f.label :allow_mfa_for_subgroups, class: 'form-check-label' do
         = _('Allow subgroups to set up their own two-factor authentication rules')
diff --git a/changelogs/unreleased/247184-instument-file-by-file-mrs.yml b/changelogs/unreleased/247184-instument-file-by-file-mrs.yml
new file mode 100644
index 00000000000..5be326c05a3
--- /dev/null
+++ b/changelogs/unreleased/247184-instument-file-by-file-mrs.yml
@@ -0,0 +1,5 @@
+---
+title: Instrument viewing merge request diffs file by file
+merge_request: 48470
+author:
+type: added
diff --git a/changelogs/unreleased/pb-handle-git-errors-cleanup-refs.yml b/changelogs/unreleased/pb-handle-git-errors-cleanup-refs.yml
new file mode 100644
index 00000000000..f60593b8c5d
--- /dev/null
+++ b/changelogs/unreleased/pb-handle-git-errors-cleanup-refs.yml
@@ -0,0 +1,5 @@
+---
+title: Handle git errors when cleaning up MR refs
+merge_request: 50250
+author:
+type: fixed
diff --git a/changelogs/unreleased/update-gitlab-runner-helm-chart-to-0-24-0.yml b/changelogs/unreleased/update-gitlab-runner-helm-chart-to-0-24-0.yml
new file mode 100644
index 00000000000..ce95e0400d4
--- /dev/null
+++ b/changelogs/unreleased/update-gitlab-runner-helm-chart-to-0-24-0.yml
@@ -0,0 +1,5 @@
+---
+title: Update GitLab Runner Helm Chart to 0.24.0
+merge_request: 50377
+author:
+type: other
diff --git a/config/feature_flags/development/usage_data_i_code_review_mr_diffs.yml b/config/feature_flags/development/usage_data_i_code_review_mr_diffs.yml
new file mode 100644
index 00000000000..a85ceaf2520
--- /dev/null
+++ b/config/feature_flags/development/usage_data_i_code_review_mr_diffs.yml
@@ -0,0 +1,8 @@
+---
+name: usage_data_i_code_review_mr_diffs
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/48470
+rollout_issue_url:
+milestone: '13.7'
+type: development
+group: group::code review
+default_enabled: true
diff --git a/config/feature_flags/development/usage_data_i_code_review_mr_single_file_diffs.yml b/config/feature_flags/development/usage_data_i_code_review_mr_single_file_diffs.yml
new file mode 100644
index 00000000000..cc9623f6cf4
--- /dev/null
+++ b/config/feature_flags/development/usage_data_i_code_review_mr_single_file_diffs.yml
@@ -0,0 +1,8 @@
+---
+name: usage_data_i_code_review_mr_single_file_diffs
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/48470
+rollout_issue_url:
+milestone: '13.7'
+type: development
+group: group::code review
+default_enabled: true
diff --git a/config/feature_flags/development/usage_data_i_code_review_user_single_file_diffs.yml b/config/feature_flags/development/usage_data_i_code_review_user_single_file_diffs.yml
new file mode 100644
index 00000000000..f77b15f9442
--- /dev/null
+++ b/config/feature_flags/development/usage_data_i_code_review_user_single_file_diffs.yml
@@ -0,0 +1,8 @@
+---
+name: usage_data_i_code_review_user_single_file_diffs
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/48470
+rollout_issue_url:
+milestone: '13.7'
+type: development
+group: group::code review
+default_enabled: true
diff --git a/db/fixtures/development/03_project.rb b/db/fixtures/development/03_project.rb
index 596c5e81a2e..e879db84e68 100644
--- a/db/fixtures/development/03_project.rb
+++ b/db/fixtures/development/03_project.rb
@@ -113,6 +113,7 @@ class Gitlab::Seeder::Projects
       group.save!
 
       group.add_owner(User.first)
+      group.create_namespace_settings
     end
 
     project_path.gsub!(".git", "")
diff --git a/doc/administration/nfs.md b/doc/administration/nfs.md
index 1e2ac531329..bddf770180b 100644
--- a/doc/administration/nfs.md
+++ b/doc/administration/nfs.md
@@ -15,9 +15,10 @@ For data objects such as LFS, Uploads, Artifacts, etc., an [Object Storage servi
 is recommended over NFS where possible, due to better performance.
 
 WARNING:
-From GitLab 13.0, using NFS for Git repositories is deprecated. In GitLab 14.0,
-support for NFS for Git repositories is scheduled to be removed. Upgrade to
-[Gitaly Cluster](gitaly/praefect.md) as soon as possible.
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](gitaly/praefect.md)
+as soon as possible.
 
 Filesystem performance can impact overall GitLab performance, especially for
 actions that read or write to Git repositories. For steps you can use to test
diff --git a/doc/administration/reference_architectures/10k_users.md b/doc/administration/reference_architectures/10k_users.md
index 216d3867d0a..69e17c28e54 100644
--- a/doc/administration/reference_architectures/10k_users.md
+++ b/doc/administration/reference_architectures/10k_users.md
@@ -2125,6 +2125,12 @@ to use GitLab Pages, this currently [requires NFS](troubleshooting.md#gitlab-pag
 
 See how to [configure NFS](../nfs.md).
 
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
+
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
     Back to setup components <i class="fa fa-angle-double-up" aria-hidden="true"></i>
diff --git a/doc/administration/reference_architectures/25k_users.md b/doc/administration/reference_architectures/25k_users.md
index c5a8c3927c0..03e340bdb88 100644
--- a/doc/administration/reference_architectures/25k_users.md
+++ b/doc/administration/reference_architectures/25k_users.md
@@ -2125,6 +2125,12 @@ to use GitLab Pages, this currently [requires NFS](troubleshooting.md#gitlab-pag
 
 See how to [configure NFS](../nfs.md).
 
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
+
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
     Back to setup components <i class="fa fa-angle-double-up" aria-hidden="true"></i>
diff --git a/doc/administration/reference_architectures/2k_users.md b/doc/administration/reference_architectures/2k_users.md
index c341ff5baec..6158fabb8bd 100644
--- a/doc/administration/reference_architectures/2k_users.md
+++ b/doc/administration/reference_architectures/2k_users.md
@@ -954,7 +954,13 @@ along with [Gitaly](#configure-gitaly), are recommended over using NFS whenever
 possible. However, if you intend to use GitLab Pages,
 [you must use NFS](troubleshooting.md#gitlab-pages-requires-nfs).
 
-For information about configuring NFS, see the [NFS documentation page](../nfs.md).
+See how to [configure NFS](../nfs.md).
+
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
 
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
diff --git a/doc/administration/reference_architectures/3k_users.md b/doc/administration/reference_architectures/3k_users.md
index d9eab28bfd6..670b86913cb 100644
--- a/doc/administration/reference_architectures/3k_users.md
+++ b/doc/administration/reference_architectures/3k_users.md
@@ -1843,6 +1843,12 @@ to use GitLab Pages, this currently [requires NFS](troubleshooting.md#gitlab-pag
 
 See how to [configure NFS](../nfs.md).
 
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
+
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
     Back to setup components <i class="fa fa-angle-double-up" aria-hidden="true"></i>
diff --git a/doc/administration/reference_architectures/50k_users.md b/doc/administration/reference_architectures/50k_users.md
index f76c8a8a877..91b3b022365 100644
--- a/doc/administration/reference_architectures/50k_users.md
+++ b/doc/administration/reference_architectures/50k_users.md
@@ -2125,6 +2125,12 @@ to use GitLab Pages, this currently [requires NFS](troubleshooting.md#gitlab-pag
 
 See how to [configure NFS](../nfs.md).
 
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
+
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
     Back to setup components <i class="fa fa-angle-double-up" aria-hidden="true"></i>
diff --git a/doc/administration/reference_architectures/5k_users.md b/doc/administration/reference_architectures/5k_users.md
index 6a0547aeaf9..6d7511f67db 100644
--- a/doc/administration/reference_architectures/5k_users.md
+++ b/doc/administration/reference_architectures/5k_users.md
@@ -1841,6 +1841,12 @@ to use GitLab Pages, this currently [requires NFS](troubleshooting.md#gitlab-pag
 
 See how to [configure NFS](../nfs.md).
 
+WARNING:
+From GitLab 13.0, using NFS for Git repositories is deprecated.
+From GitLab 14.0, technical support for NFS for Git repositories
+will no longer be provided. Upgrade to [Gitaly Cluster](../gitaly/praefect.md)
+as soon as possible.
+
 <div align="right">
   <a type="button" class="btn btn-default" href="#setup-components">
     Back to setup components <i class="fa fa-angle-double-up" aria-hidden="true"></i>
diff --git a/doc/administration/reference_architectures/troubleshooting.md b/doc/administration/reference_architectures/troubleshooting.md
index 406ff57c66d..cd1a2bc91df 100644
--- a/doc/administration/reference_architectures/troubleshooting.md
+++ b/doc/administration/reference_architectures/troubleshooting.md
@@ -23,12 +23,12 @@ with the Fog library that GitLab uses. Symptoms include:
 ### GitLab Pages requires NFS
 
 If you intend to use [GitLab Pages](../../user/project/pages/index.md), this currently requires
-[NFS](../nfs.md). There is [work in progress](https://gitlab.com/gitlab-org/gitlab-pages/-/issues/196)
-to remove this dependency. In the future, GitLab Pages may use
-[object storage](https://gitlab.com/gitlab-org/gitlab/-/issues/208135).
+[NFS](../nfs.md). There is [work in progress](https://gitlab.com/groups/gitlab-org/-/epics/3901)
+to remove this dependency. In the future, GitLab Pages will use
+object storage.
 
 The dependency on disk storage also prevents Pages being deployed using the
-[GitLab Helm chart](https://gitlab.com/gitlab-org/charts/gitlab/-/issues/37).
+[GitLab Helm chart](https://gitlab.com/groups/gitlab-org/-/epics/4283).
 
 ### Incremental logging is required for CI to use object storage
 
diff --git a/lib/gitlab/usage_data_counters/known_events/common.yml b/lib/gitlab/usage_data_counters/known_events/common.yml
index 25cf388aedf..0d0c787d6d2 100644
--- a/lib/gitlab/usage_data_counters/known_events/common.yml
+++ b/lib/gitlab/usage_data_counters/known_events/common.yml
@@ -425,3 +425,18 @@
   redis_slot: snippets
   aggregation: weekly
   feature_flag: usage_data_i_snippets_show
+- name: i_code_review_mr_diffs
+  redis_slot: code_review
+  category: code_review
+  aggregation: weekly
+  feature_flag: usage_data_i_code_review_mr_diffs
+- name: i_code_review_user_single_file_diffs
+  redis_slot: code_review
+  category: code_review
+  aggregation: weekly
+  feature_flag: usage_data_i_code_review_user_single_file_diffs
+- name: i_code_review_mr_single_file_diffs
+  redis_slot: code_review
+  category: code_review
+  aggregation: weekly
+  feature_flag: usage_data_i_code_review_mr_single_file_diffs
diff --git a/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb b/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb
new file mode 100644
index 00000000000..ef90370ce2d
--- /dev/null
+++ b/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module UsageDataCounters
+    module MergeRequestActivityUniqueCounter
+      MR_DIFFS_ACTION = 'i_code_review_mr_diffs'
+      MR_DIFFS_SINGLE_FILE_ACTION = 'i_code_review_mr_single_file_diffs'
+      MR_DIFFS_USER_SINGLE_FILE_ACTION = 'i_code_review_user_single_file_diffs'
+
+      class << self
+        def track_mr_diffs_action(merge_request:)
+          track_unique_action_by_merge_request(MR_DIFFS_ACTION, merge_request)
+        end
+
+        def track_mr_diffs_single_file_action(merge_request:, user:)
+          track_unique_action_by_merge_request(MR_DIFFS_SINGLE_FILE_ACTION, merge_request)
+          track_unique_action_by_user(MR_DIFFS_USER_SINGLE_FILE_ACTION, user)
+        end
+
+        private
+
+        def track_unique_action_by_merge_request(action, merge_request)
+          track_unique_action(action, merge_request.id)
+        end
+
+        def track_unique_action_by_user(action, user)
+          return unless user
+
+          track_unique_action(action, user.id)
+        end
+
+        def track_unique_action(action, value)
+          Gitlab::UsageDataCounters::HLLRedisCounter.track_usage_event(action, value)
+        end
+      end
+    end
+  end
+end
diff --git a/qa/qa/page/component/snippet.rb b/qa/qa/page/component/snippet.rb
index 459c02ec883..b98c429df8c 100644
--- a/qa/qa/page/component/snippet.rb
+++ b/qa/qa/page/component/snippet.rb
@@ -78,6 +78,11 @@ module QA
           base.view 'app/assets/javascripts/snippets/components/embed_dropdown.vue' do
             element :copy_button
           end
+
+          base.view 'app/assets/javascripts/blob/components/blob_header_default_actions.vue' do
+            element :default_actions_container
+            element :copy_contents_button
+          end
         end
 
         def has_snippet_title?(snippet_title)
@@ -182,7 +187,10 @@ module QA
         def add_comment(comment)
           fill_element(:note_field, comment)
           click_element(:comment_button)
-          wait_until(reload: false) { has_element?(:note_author_content) }
+
+          unless has_element?(:note_author_content)
+            raise ElementNotFound, "Comment did not appear as expected"
+          end
         end
 
         def has_comment_author?(author_username)
@@ -207,7 +215,10 @@ module QA
           click_element(:edit_comment_button)
           fill_element(:edit_note_field, comment)
           click_element(:save_comment_button)
-          wait_until(reload: false) { has_element?(:note_author_content) }
+
+          unless has_element?(:note_author_content)
+            raise ElementNotFound, "Comment did not appear as expected"
+          end
         end
 
         def delete_comment(comment)
@@ -215,7 +226,32 @@ module QA
           accept_alert do
             click_element(:delete_comment_button)
           end
-          wait_until(reload: false) { has_no_text?(comment) }
+
+          unless has_no_element?(:note_content, text: comment)
+            raise ElementNotFound, "Comment was not removed as expected"
+          end
+        end
+
+        def click_copy_file_contents(file_number = nil)
+          if file_number
+            within_element_by_index(:default_actions_container, file_number - 1) do
+              click_element(:copy_contents_button)
+            end
+          else
+            within_element(:default_actions_container) do
+              click_element(:copy_contents_button)
+            end
+          end
+        end
+
+        def copy_file_contents_to_comment(file_number = nil)
+          click_copy_file_contents(file_number)
+          send_keys_to_element(:note_field, [:shift, :insert])
+          click_element(:comment_button)
+
+          unless has_element?(:note_author_content)
+            raise ElementNotFound, "Comment did not appear as expected"
+          end
         end
       end
     end
diff --git a/qa/qa/specs/features/browser_ui/3_create/snippet/copy_snippet_file_contents_spec.rb b/qa/qa/specs/features/browser_ui/3_create/snippet/copy_snippet_file_contents_spec.rb
new file mode 100644
index 00000000000..1670ba56064
--- /dev/null
+++ b/qa/qa/specs/features/browser_ui/3_create/snippet/copy_snippet_file_contents_spec.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+module QA
+  RSpec.describe 'Create' do
+    describe 'Multiple file snippet' do
+      let(:first_file_content) { 'First file content' }
+      let(:second_file_content) { 'Second file content' }
+      let(:third_file_content) { 'Third file content' }
+
+      let(:personal_snippet) do
+        Resource::Snippet.fabricate_via_api! do |snippet|
+          snippet.title = 'Personal snippet to copy file contents from'
+          snippet.file_name = 'First file name'
+          snippet.file_content = first_file_content
+
+          snippet.add_files do |files|
+            files.append(name: 'Second file name', content: second_file_content)
+            files.append(name: 'Third file name', content: third_file_content)
+          end
+        end
+      end
+
+      let(:project_snippet) do
+        Resource::ProjectSnippet.fabricate_via_api! do |snippet|
+          snippet.title = 'Project snippet to copy file contents from'
+          snippet.file_name = 'First file name'
+          snippet.file_content = first_file_content
+
+          snippet.add_files do |files|
+            files.append(name: 'Second file name', content: second_file_content)
+            files.append(name: 'Third file name', content: third_file_content)
+          end
+        end
+      end
+
+      let(:files) do
+        [
+            {
+                number: 1,
+                content: first_file_content
+            },
+            {
+                number: 2,
+                content: second_file_content
+            },
+            {
+                number: 3,
+                content: third_file_content
+            }
+        ]
+      end
+
+      before do
+        Flow::Login.sign_in
+      end
+
+      shared_examples 'copying snippet file contents' do |snippet_type|
+        it "copies file contents of a multi-file #{snippet_type} to a comment and verifies them" do
+          send(snippet_type).visit!
+
+          files.each do |files|
+            Page::Dashboard::Snippet::Show.perform do |snippet|
+              snippet.copy_file_contents_to_comment(files[:number])
+              expect(snippet).to have_comment_content(files[:content])
+              snippet.delete_comment(files[:content])
+            end
+          end
+        end
+      end
+
+      it_behaves_like 'copying snippet file contents', :personal_snippet
+      it_behaves_like 'copying snippet file contents', :project_snippet
+    end
+  end
+end
diff --git a/qa/qa/specs/features/browser_ui/3_create/snippet/share_snippet_spec.rb b/qa/qa/specs/features/browser_ui/3_create/snippet/share_snippet_spec.rb
index 971c5371d44..751424222ba 100644
--- a/qa/qa/specs/features/browser_ui/3_create/snippet/share_snippet_spec.rb
+++ b/qa/qa/specs/features/browser_ui/3_create/snippet/share_snippet_spec.rb
@@ -7,7 +7,7 @@ module QA
         Resource::Snippet.fabricate! do |snippet|
           snippet.title = 'Shared snippet'
           snippet.visibility = 'Public'
-          snippet.file_content = 'code.py'
+          snippet.file_name = 'code.py'
           snippet.file_content = 'code to be shared'
         end
       end
diff --git a/spec/controllers/projects/merge_requests/diffs_controller_spec.rb b/spec/controllers/projects/merge_requests/diffs_controller_spec.rb
index f4f0a9f8108..2028e9daf14 100644
--- a/spec/controllers/projects/merge_requests/diffs_controller_spec.rb
+++ b/spec/controllers/projects/merge_requests/diffs_controller_spec.rb
@@ -378,6 +378,57 @@ RSpec.describe Projects::MergeRequests::DiffsController do
 
         expect(response).to have_gitlab_http_status(:ok)
       end
+
+      it 'tracks mr_diffs event' do
+        expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+          .to receive(:track_mr_diffs_action)
+          .with(merge_request: merge_request)
+
+        subject
+      end
+
+      context 'when DNT is enabled' do
+        before do
+          request.headers['DNT'] = '1'
+        end
+
+        it 'does not track any mr_diffs event' do
+          expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+            .not_to receive(:track_mr_diffs_action)
+
+          expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+            .not_to receive(:track_mr_diffs_single_file_action)
+
+          subject
+        end
+      end
+
+      context 'when user has view_diffs_file_by_file set to false' do
+        before do
+          user.update!(view_diffs_file_by_file: false)
+        end
+
+        it 'does not track single_file_diffs events' do
+          expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+            .not_to receive(:track_mr_diffs_single_file_action)
+
+          subject
+        end
+      end
+
+      context 'when user has view_diffs_file_by_file set to true' do
+        before do
+          user.update!(view_diffs_file_by_file: true)
+        end
+
+        it 'tracks single_file_diffs events' do
+          expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+            .to receive(:track_mr_diffs_single_file_action)
+            .with(merge_request: merge_request, user: user)
+
+          subject
+        end
+      end
     end
 
     def collection_arguments(pagination_data = {})
diff --git a/spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb b/spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb
index b6a60c09d3d..f2ec4526464 100644
--- a/spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb
+++ b/spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb
@@ -45,7 +45,8 @@ RSpec.describe Gitlab::UsageDataCounters::HLLRedisCounter, :clean_gitlab_redis_s
         'debian_packages',
         'container_packages',
         'tag_packages',
-        'snippets'
+        'snippets',
+        'code_review'
       )
     end
   end
diff --git a/spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb b/spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb
new file mode 100644
index 00000000000..ecead53abf2
--- /dev/null
+++ b/spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter, :clean_gitlab_redis_shared_state do
+  let(:merge_request) { build(:merge_request, id: 1) }
+  let(:user) { build(:user, id: 1) }
+
+  shared_examples_for 'a tracked merge request unique event' do
+    specify do
+      expect { 3.times { subject } }
+        .to change {
+          Gitlab::UsageDataCounters::HLLRedisCounter.unique_events(
+            event_names: action,
+            start_date: 2.weeks.ago,
+            end_date: 2.weeks.from_now
+          )
+        }
+        .by(1)
+    end
+  end
+
+  describe '.track_mr_diffs_action' do
+    subject { described_class.track_mr_diffs_action(merge_request: merge_request) }
+
+    it_behaves_like 'a tracked merge request unique event' do
+      let(:action) { described_class::MR_DIFFS_ACTION }
+    end
+  end
+
+  describe '.track_mr_diffs_single_file_action' do
+    subject { described_class.track_mr_diffs_single_file_action(merge_request: merge_request, user: user) }
+
+    it_behaves_like 'a tracked merge request unique event' do
+      let(:action) { described_class::MR_DIFFS_SINGLE_FILE_ACTION }
+    end
+
+    it_behaves_like 'a tracked merge request unique event' do
+      let(:action) { described_class::MR_DIFFS_USER_SINGLE_FILE_ACTION }
+    end
+  end
+end
diff --git a/spec/services/merge_requests/cleanup_refs_service_spec.rb b/spec/services/merge_requests/cleanup_refs_service_spec.rb
index 38c0e204e54..a1822a4d5ba 100644
--- a/spec/services/merge_requests/cleanup_refs_service_spec.rb
+++ b/spec/services/merge_requests/cleanup_refs_service_spec.rb
@@ -91,6 +91,26 @@ RSpec.describe MergeRequests::CleanupRefsService do
         it_behaves_like 'service that does not clean up merge request refs'
       end
 
+      context 'when a git error is raised' do
+        context 'Gitlab::Git::Repository::GitError' do
+          before do
+            allow(merge_request.project.repository).to receive(:delete_refs).and_raise(Gitlab::Git::Repository::GitError)
+          end
+
+          it_behaves_like 'service that does not clean up merge request refs'
+        end
+
+        context 'Gitlab::Git::CommandError' do
+          before do
+            allow_next_instance_of(Gitlab::Git::KeepAround) do |keep_around|
+              expect(keep_around).to receive(:kept_around?).and_raise(Gitlab::Git::CommandError)
+            end
+          end
+
+          it_behaves_like 'service that does not clean up merge request refs'
+        end
+      end
+
       context 'when cleanup schedule fails to update' do
         before do
           allow(merge_request.cleanup_schedule).to receive(:update).and_return(false)