Automatic merge of gitlab-org/gitlab master

.gitlab/ci/rails.gitlab-ci.yml

@@ -377,7 +377,7 @@ db:rollback:
     - bundle exec rake db:migrate SKIP_SCHEMA_VERSION_CHECK=true
 
 db:gitlabcom-database-testing:
-  extends: .rails:rules:ee-and-foss-mr-with-migration
+  extends: .rails:rules:db:gitlabcom-database-testing
   stage: test
   image: ruby:2.7-alpine
   needs: []

.gitlab/ci/rules.gitlab-ci.yml

@@ -523,6 +523,13 @@
       changes: *db-patterns
     - <<: *if-merge-request-title-run-all-rspec
 
+.rails:rules:db:gitlabcom-database-testing:
+  rules:
+    - if: '$GITLABCOM_DATABASE_TESTING_TRIGGER_TOKEN == null'
+      when: never
+    - <<: *if-merge-request
+      changes: *db-patterns
+
 .rails:rules:ee-and-foss-unit:
   rules:
     - changes: *backend-patterns

GITALY_SERVER_VERSION

-c38393255d22bf3533ca8b8714f614411f10fc30
+86d933c0a993eabbff4c725da3cff067f371e641

app/controllers/projects/merge_requests/diffs_controller.rb

@@ -122,10 +122,7 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
       end
     end
 
-    if render_merge_ref_head_diff?
-      return CompareService.new(@project, @merge_request.merge_ref_head.sha)
-        .execute(@project, @merge_request.target_branch)
-    end
+    return @merge_request.merge_head_diff if render_merge_ref_head_diff?
 
     if @start_sha
       @merge_request_diff.compare_with(@start_sha)

app/models/merge_request.rb

@@ -50,12 +50,15 @@ class MergeRequest < ApplicationRecord
       end
     end
 
-  has_many :merge_request_diffs
+  has_many :merge_request_diffs,
+    -> { regular }, inverse_of: :merge_request
   has_many :merge_request_context_commits, inverse_of: :merge_request
   has_many :merge_request_context_commit_diff_files, through: :merge_request_context_commits, source: :diff_files
 
   has_one :merge_request_diff,
-    -> { order('merge_request_diffs.id DESC') }, inverse_of: :merge_request
+    -> { regular.order('merge_request_diffs.id DESC') }, inverse_of: :merge_request
+  has_one :merge_head_diff,
+    -> { merge_head }, inverse_of: :merge_request, class_name: 'MergeRequestDiff'
   has_one :cleanup_schedule, inverse_of: :merge_request
 
   belongs_to :latest_merge_request_diff, class_name: 'MergeRequestDiff'
@@ -476,13 +479,17 @@ class MergeRequest < ApplicationRecord
   # This is used after project import, to reset the IDs to the correct
   # values. It is not intended to be called without having already scoped the
   # relation.
+  #
+  # Only set `regular` merge request diffs as latest so `merge_head` diff
+  # won't be considered as `MergeRequest#merge_request_diff`.
   def self.set_latest_merge_request_diff_ids!
-    update = '
+    update = "
       latest_merge_request_diff_id = (
         SELECT MAX(id)
         FROM merge_request_diffs
         WHERE merge_requests.id = merge_request_diffs.merge_request_id
-      )'.squish
+        AND merge_request_diffs.diff_type = #{MergeRequestDiff.diff_types[:regular]}
+      )".squish
 
     self.each_batch do |batch|
       batch.update_all(update)
@@ -921,7 +928,7 @@ class MergeRequest < ApplicationRecord
   def create_merge_request_diff
     fetch_ref!
 
-    # n+1: https://gitlab.com/gitlab-org/gitlab-foss/issues/37435
+    # n+1: https://gitlab.com/gitlab-org/gitlab/-/issues/19377
     Gitlab::GitalyClient.allow_n_plus_1_calls do
       merge_request_diffs.create!
       reload_merge_request_diff
@@ -995,7 +1002,7 @@ class MergeRequest < ApplicationRecord
   # rubocop: enable CodeReuse/ServiceClass
 
   def diffable_merge_ref?
-    open? && merge_ref_head.present? && (Feature.enabled?(:display_merge_conflicts_in_diff, project) || can_be_merged?)
+    open? && merge_head_diff.present? && (Feature.enabled?(:display_merge_conflicts_in_diff, project) || can_be_merged?)
   end
 
   # Returns boolean indicating the merge_status should be rechecked in order to

app/models/merge_request_diff.rb

@@ -32,6 +32,7 @@ class MergeRequestDiff < ApplicationRecord
   has_many :merge_request_diff_commits, -> { order(:merge_request_diff_id, :relative_order) }
 
   validates :base_commit_sha, :head_commit_sha, :start_commit_sha, sha: true
+  validates :merge_request_id, uniqueness: { scope: :diff_type }, if: :merge_head?
 
   state_machine :state, initial: :empty do
     event :clean do
@@ -50,6 +51,11 @@ class MergeRequestDiff < ApplicationRecord
     state :overflow_diff_lines_limit
   end
 
+  enum diff_type: {
+    regular: 1,
+    merge_head: 2
+  }
+
   scope :with_files, -> { without_states(:without_files, :empty) }
   scope :viewable, -> { without_state(:empty) }
   scope :by_commit_sha, ->(sha) do
@@ -72,6 +78,7 @@ class MergeRequestDiff < ApplicationRecord
 
     join_condition = merge_requests[:id].eq(mr_diffs[:merge_request_id])
       .and(mr_diffs[:id].not_eq(merge_requests[:latest_merge_request_diff_id]))
+      .and(mr_diffs[:diff_type].eq(diff_types[:regular]))
 
     arel_join = mr_diffs.join(merge_requests).on(join_condition)
     joins(arel_join.join_sources)
@@ -196,6 +203,10 @@ class MergeRequestDiff < ApplicationRecord
   end
 
   def set_as_latest_diff
+    # Don't set merge_head diff as latest so it won't get considered as the
+    # MergeRequest#merge_request_diff.
+    return if merge_head?
+
     MergeRequest
       .where('id = ? AND COALESCE(latest_merge_request_diff_id, 0) < ?', self.merge_request_id, self.id)
       .update_all(latest_merge_request_diff_id: self.id)
@@ -203,8 +214,16 @@ class MergeRequestDiff < ApplicationRecord
 
   def ensure_commit_shas
     self.start_commit_sha ||= merge_request.target_branch_sha
-    self.head_commit_sha  ||= merge_request.source_branch_sha
-    self.base_commit_sha  ||= find_base_sha
+
+    if merge_head? && merge_request.merge_ref_head.present?
+      diff_refs = merge_request.merge_ref_head.diff_refs
+
+      self.head_commit_sha  ||= diff_refs.head_sha
+      self.base_commit_sha  ||= diff_refs.base_sha
+    else
+      self.head_commit_sha  ||= merge_request.source_branch_sha
+      self.base_commit_sha  ||= find_base_sha
+    end
   end
 
   # Override head_commit_sha to keep compatibility with merge request diff

app/services/merge_requests/mergeability_check_service.rb

@@ -114,6 +114,7 @@ module MergeRequests
 
       merge_to_ref_success = merge_to_ref
 
+      reload_merge_head_diff
       update_diff_discussion_positions! if merge_to_ref_success
 
       if merge_to_ref_success && can_git_merge?
@@ -123,6 +124,10 @@ module MergeRequests
       end
     end
 
+    def reload_merge_head_diff
+      MergeRequests::ReloadMergeHeadDiffService.new(merge_request).execute
+    end
+
     def update_diff_discussion_positions!
       Discussions::CaptureDiffNotePositionsService.new(merge_request).execute
     end
@@ -153,6 +158,7 @@ module MergeRequests
     def merge_to_ref
       params = { allow_conflicts: Feature.enabled?(:display_merge_conflicts_in_diff, project) }
       result = MergeRequests::MergeToRefService.new(project, merge_request.author, params).execute(merge_request)
+
       result[:status] == :success
     end
 

app/services/merge_requests/reload_merge_head_diff_service.rb

+# frozen_string_literal: true
+
+module MergeRequests
+  class ReloadMergeHeadDiffService
+    include BaseServiceUtility
+
+    def initialize(merge_request)
+      @merge_request = merge_request
+    end
+
+    def execute
+      return error("default_merge_ref_for_diffs feature flag is disabled") unless enabled?
+      return error("Merge request has no merge ref head.") unless merge_request.merge_ref_head.present?
+
+      error_msg = recreate_merge_head_diff
+
+      return error(error_msg) if error_msg
+
+      success
+    end
+
+    private
+
+    attr_reader :merge_request
+
+    def enabled?
+      Feature.enabled?(:default_merge_ref_for_diffs, merge_request.project)
+    end
+
+    def recreate_merge_head_diff
+      merge_request.merge_head_diff&.destroy!
+
+      # n+1: https://gitlab.com/gitlab-org/gitlab/-/issues/19377
+      Gitlab::GitalyClient.allow_n_plus_1_calls do
+        merge_request.create_merge_head_diff!
+      end
+
+      # Reset the merge request so it won't load the merge head diff as the
+      # MergeRequest#merge_request_diff.
+      merge_request.reset
+
+      nil
+    rescue StandardError => e
+      message = "Failed to recreate merge head diff: #{e.message}"
+
+      Gitlab::AppLogger.error(message: message, merge_request_id: merge_request.id)
+      message
+    end
+  end
+end

changelogs/unreleased/292507-batch-merge-ref-diff.yml

+---
+title: Support batch loading of merge head diffs
+merge_request: 51078
+author:
+type: performance

db/migrate/20210107105306_add_diff_type_to_merge_request_diffs.rb

+# frozen_string_literal: true
+
+class AddDiffTypeToMergeRequestDiffs < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  UNIQUE_INDEX_NAME = 'index_merge_request_diffs_on_unique_merge_request_id'
+
+  def up
+    unless column_exists?(:merge_request_diffs, :diff_type)
+      with_lock_retries do
+        add_column :merge_request_diffs, :diff_type, :integer, null: false, limit: 2, default: 1
+      end
+    end
+
+    add_concurrent_index :merge_request_diffs, :merge_request_id, unique: true, where: 'diff_type = 2', name: UNIQUE_INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name(:merge_request_diffs, UNIQUE_INDEX_NAME)
+
+    if column_exists?(:merge_request_diffs, :diff_type)
+      with_lock_retries do
+        remove_column :merge_request_diffs, :diff_type
+      end
+    end
+  end
+end

db/schema_migrations/20210107105306

+f76ce27a82f4773dcda324d79cc93a044f21317dbb9fdff035879502b5752da3
\ No newline at end of file

db/structure.sql

@@ -14011,6 +14011,7 @@ CREATE TABLE merge_request_diffs (
     stored_externally boolean,
     files_count smallint,
     sorted boolean DEFAULT false NOT NULL,
+    diff_type smallint DEFAULT 1 NOT NULL,
     CONSTRAINT check_93ee616ac9 CHECK ((external_diff_store IS NOT NULL))
 );
 
@@ -22242,6 +22243,8 @@ CREATE INDEX index_merge_request_diffs_on_external_diff_store ON merge_request_d
 
 CREATE INDEX index_merge_request_diffs_on_merge_request_id_and_id ON merge_request_diffs USING btree (merge_request_id, id);
 
+CREATE UNIQUE INDEX index_merge_request_diffs_on_unique_merge_request_id ON merge_request_diffs USING btree (merge_request_id) WHERE (diff_type = 2);
+
 CREATE INDEX index_merge_request_metrics_on_first_deployed_to_production_at ON merge_request_metrics USING btree (first_deployed_to_production_at);
 
 CREATE INDEX index_merge_request_metrics_on_latest_closed_at ON merge_request_metrics USING btree (latest_closed_at) WHERE (latest_closed_at IS NOT NULL);

doc/administration/pages/index.md

@@ -928,6 +928,20 @@ For example, if there is a connection timeout:
 error="failed to connect to internal Pages API: Get \"https://gitlab.example.com:3000/api/v4/internal/pages/status\": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)"
 ```
 
+### Pages cannot communicate with an instance of the GitLab API
+
+If you use the default value for `domain_config_source=auto` and run multiple instances of GitLab
+Pages, you may see intermittent 502 error responses while serving Pages content. You may also see
+the following warning in the Pages logs:
+
+```plaintext
+WARN[0010] Pages cannot communicate with an instance of the GitLab API. Please sync your gitlab-secrets.json file https://gitlab.com/gitlab-org/gitlab-pages/-/issues/535#workaround. error="pages endpoint unauthorized"
+```
+
+This can happen if your `gitlab-secrets.json` file is out of date between GitLab Rails and GitLab
+Pages. Follow steps 8-10 of [Running GitLab Pages on a separate server](#running-gitlab-pages-on-a-separate-server),
+in all of your GitLab Pages instances.
+
 ### 500 error with `securecookie: failed to generate random iv` and `Failed to save the session`
 
 This problem most likely results from an [out-dated operating system](https://docs.gitlab.com/omnibus/package-information/deprecated_os.html).

ee/app/assets/javascripts/analytics/merge_request_analytics/components/throughput_chart.vue

@@ -6,7 +6,8 @@ import ChartSkeletonLoader from '~/vue_shared/components/resizable_chart/skeleto
 import { filterToQueryObject } from '~/vue_shared/components/filtered_search_bar/filtered_search_utils';
 import throughputChartQueryBuilder from '../graphql/throughput_chart_query_builder';
 import { THROUGHPUT_CHART_STRINGS } from '../constants';
-import { formatThroughputChartData } from '../utils';
+import { formatThroughputChartData, computeMttmData } from '../utils';
+import ThroughputStats from './throughput_stats.vue';
 
 export default {
   name: 'ThroughputChart',
@@ -14,6 +15,7 @@ export default {
     GlAreaChart,
     GlAlert,
     ChartSkeletonLoader,
+    ThroughputStats,
   },
   inject: ['fullPath'],
   props: {
@@ -88,7 +90,7 @@ export default {
     formattedThroughputChartData() {
       return formatThroughputChartData(this.throughputChartData);
     },
-    chartDataLoading() {
+    isLoading() {
       return !this.hasError && this.$apollo.queries.throughputChartData.loading;
     },
     chartDataAvailable() {
@@ -102,6 +104,9 @@ export default {
           : THROUGHPUT_CHART_STRINGS.NO_DATA,
       };
     },
+    singleStatsValues() {
+      return [computeMttmData(this.throughputChartData)];
+    },
   },
   strings: {
     chartTitle: THROUGHPUT_CHART_STRINGS.CHART_TITLE,
@@ -111,11 +116,12 @@ export default {
 </script>
 <template>
   <div>
+    <throughput-stats :stats="singleStatsValues" :is-loading="isLoading" />
     <h4 data-testid="chartTitle">{{ $options.strings.chartTitle }}</h4>
     <div class="gl-text-gray-500" data-testid="chartDescription">
       {{ $options.strings.chartDescription }}
     </div>
-    <chart-skeleton-loader v-if="chartDataLoading" />
+    <chart-skeleton-loader v-if="isLoading" />
     <gl-area-chart
       v-else-if="chartDataAvailable"
       :data="formattedThroughputChartData"

ee/app/assets/javascripts/analytics/merge_request_analytics/components/throughput_stats.vue

+<script>
+import { GlSkeletonLoader } from '@gitlab/ui';
+import { GlSingleStat } from '@gitlab/ui/dist/charts';
+import { STAT_LOADER_HEIGHT } from '../constants';
+
+export default {
+  name: 'ThroughputStats',
+  components: {
+    GlSingleStat,
+    GlSkeletonLoader,
+  },
+  props: {
+    stats: {
+      type: Array,
+      required: true,
+    },
+    isLoading: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  loaderHeight: STAT_LOADER_HEIGHT,
+};
+</script>
+<template>
+  <div class="gl-my-7 gl-display-flex">
+    <div v-for="stat in stats" :key="stat.title">
+      <gl-skeleton-loader v-if="isLoading" :height="$options.loaderHeight" />
+      <gl-single-stat v-else :value="stat.value" :title="stat.title" :unit="stat.unit" />
+    </div>
+  </div>
+</template>

ee/app/assets/javascripts/analytics/merge_request_analytics/constants.js

 import { __ } from '~/locale';
 
 export const DEFAULT_NUMBER_OF_DAYS = 365;
+export const STAT_LOADER_HEIGHT = 46;
 export const PER_PAGE = 20;
 export const ASSIGNEES_VISIBLE = 2;
 export const AVATAR_SIZE = 24;
@@ -14,6 +15,7 @@ export const THROUGHPUT_CHART_STRINGS = {
   ERROR_FETCHING_DATA: __(
     'There was an error while fetching the chart data. Please refresh the page to try again.',
   ),
+  MTTM: __('Mean time to merge'),
 };
 
 export const THROUGHPUT_TABLE_STRINGS = {
@@ -51,3 +53,7 @@ export const PIPELINE_STATUS_ICON_CLASSES = {
   status_pending: 'gl-text-orange-500',
   default: 'gl-text-grey-500',
 };
+
+export const UNITS = {
+  DAYS: __('days'),
+};

ee/app/assets/javascripts/analytics/merge_request_analytics/graphql/throughput_chart_query_builder.js

@@ -32,7 +32,7 @@ export default (startDate = null, endDate = null) => {
         milestoneTitle: $milestoneTitle,
         sourceBranches: $sourceBranches,
         targetBranches: $targetBranches
-      ) { count }
+      ) { count, totalTimeToMerge }
     `;
   });
 

ee/app/assets/javascripts/analytics/merge_request_analytics/utils.js

@@ -4,9 +4,10 @@ import {
   dateFromParams,
   getDateInPast,
   getDayDifference,
+  secondsToDays,
 } from '~/lib/utils/datetime_utility';
 import { dateFormats } from '../shared/constants';
-import { THROUGHPUT_CHART_STRINGS, DEFAULT_NUMBER_OF_DAYS } from './constants';
+import { THROUGHPUT_CHART_STRINGS, DEFAULT_NUMBER_OF_DAYS, UNITS } from './constants';
 
 /**
  * A utility function which accepts a date range and returns
@@ -73,6 +74,42 @@ export const formatThroughputChartData = (chartData) => {
   ];
 };
 
+/**
+ * A utility function which accepts the raw throughput data
+ * and computes the mean time to merge.
+ *
+ * @param {Object} rawData the raw throughput data
+ *
+ * @return {Object} the computed MTTM data
+ */
+export const computeMttmData = (rawData) => {
+  if (!rawData) return {};
+
+  const mttmData = Object.values(rawData)
+    // eslint-disable-next-line @gitlab/require-i18n-strings
+    .filter((value) => value !== 'Project')
+    .reduce(
+      (total, monthData) => {
+        return {
+          count: total.count + monthData.count,
+          totalTimeToMerge: total.totalTimeToMerge + monthData.totalTimeToMerge,
+        };
+      },
+      {
+        count: 0,
+        totalTimeToMerge: 0,
+      },
+    );
+
+  // GlSingleStat expects a String for the 'value' prop
+  // https://gitlab.com/gitlab-org/gitlab-ui/-/issues/1152
+  return {
+    title: THROUGHPUT_CHART_STRINGS.MTTM,
+    value: `${secondsToDays(mttmData.totalTimeToMerge / mttmData.count)}`,
+    unit: UNITS.DAYS,
+  };
+};
+
 /**
  * A utility function which accepts start and end date params
  * and validates that the date range does not exceed the bounds

ee/app/views/groups/sidebar/_packages.html.haml

@@ -2,12 +2,12 @@
 
 - if group_packages_nav?
   = nav_link(controller: ['groups/packages', 'groups/registry/repositories', 'groups/dependency_proxies']) do
-    = link_to packages_link, title: _('Packages') do
+    = link_to packages_link, title: _('Packages'), data: { qa_selector: 'group_packages_item' } do
       .nav-icon-container
         = sprite_icon('package')
       %span.nav-item-name
         = _('Packages & Registries')
-    %ul.sidebar-sub-level-items
+    %ul.sidebar-sub-level-items{ data: { qa_selector: 'group_packages_submenu' } }
       = nav_link(controller: [:packages, :repositories], html_options: { class: "fly-out-top-item" } ) do
         = link_to packages_link, title: _('Packages & Registries') do
           %strong.fly-out-top-item-name
@@ -15,7 +15,7 @@
       %li.divider.fly-out-top-item
       - if group_packages_list_nav?
         = nav_link(controller: 'groups/packages') do
-          = link_to group_packages_path(@group), title: _('Packages') do
+          = link_to group_packages_path(@group), title: _('Packages'), data: { qa_selector: 'group_packages_link' } do
             %span= _('Package Registry')
       - if group_container_registry_nav?
         = nav_link(controller: 'groups/registry/repositories') do

ee/changelogs/unreleased/229389-mr-analytics-add-mttm-container-fe-2.yml

+---
+title: Add MTTM stat to MR Analytics
+merge_request: 52316
+author:
+type: added

ee/spec/frontend/analytics/merge_request_analytics/components/throughput_chart_spec.js

@@ -3,6 +3,7 @@ import { GlAreaChart } from '@gitlab/ui/dist/charts';
 import { shallowMount, createLocalVue } from '@vue/test-utils';
 import Vuex from 'vuex';
 import ThroughputChart from 'ee/analytics/merge_request_analytics/components/throughput_chart.vue';
+import ThroughputStats from 'ee/analytics/merge_request_analytics/components/throughput_stats.vue';
 import { THROUGHPUT_CHART_STRINGS } from 'ee/analytics/merge_request_analytics/constants';
 import store from 'ee/analytics/merge_request_analytics/store';
 import ChartSkeletonLoader from '~/vue_shared/components/resizable_chart/skeleton_loader.vue';
@@ -67,6 +68,10 @@ describe('ThroughputChart', () => {
       wrapper = createComponent();
     });
 
+    it('displays the throughput stats component', () => {
+      expect(wrapper.find(ThroughputStats).exists()).toBe(true);
+    });
+
     it('displays the chart title', () => {
       const chartTitle = wrapper.find('[data-testid="chartTitle"').text();
 

ee/spec/frontend/analytics/merge_request_analytics/components/throughput_stats_spec.js

+import { shallowMount } from '@vue/test-utils';
+import { GlSkeletonLoader } from '@gitlab/ui';
+import { GlSingleStat } from '@gitlab/ui/dist/charts';
+import ThroughputStats from 'ee/analytics/merge_request_analytics/components/throughput_stats';
+import { stats } from '../mock_data';
+
+describe('ThroughputStats', () => {
+  let wrapper;
+
+  const createWrapper = (props) => {
+    return shallowMount(ThroughputStats, {
+      propsData: {
+        stats,
+        ...props,
+      },
+    });
+  };
+
+  describe('default behaviour', () => {
+    beforeEach(() => {
+      wrapper = createWrapper();
+    });
+
+    it('displays a GlSingleStat component for each stat entry', () => {
+      expect(wrapper.findAll(GlSingleStat)).toHaveLength(stats.length);
+    });
+
+    it('passes the GlSingleStat the correct props', () => {
+      const component = wrapper.findAll(GlSingleStat).at(0);
+      const { title, unit, value } = stats[0];
+
+      expect(component.props('title')).toBe(title);
+      expect(component.props('unit')).toBe(unit);
+      expect(component.props('value')).toBe(value);
+    });
+
+    it('does not display any GlSkeletonLoader components', () => {
+      expect(wrapper.findAll(GlSkeletonLoader)).toHaveLength(0);
+    });
+  });
+
+  describe('loading', () => {
+    beforeEach(() => {
+      wrapper = createWrapper({ isLoading: true });
+    });
+
+    it('displays a GlSkeletonLoader component for each stat entry', () => {
+      expect(wrapper.findAll(GlSkeletonLoader)).toHaveLength(stats.length);
+    });
+
+    it('does not display any GlSingleStat components', () => {
+      expect(wrapper.findAll(GlSingleStat)).toHaveLength(0);
+    });
+  });
+});

ee/spec/frontend/analytics/merge_request_analytics/mock_data.js

@@ -8,9 +8,9 @@ export const fullPath = 'gitlab-org/gitlab';
 // We should update our tests to use fixtures instead of hardcoded mock data.
 // https://gitlab.com/gitlab-org/gitlab/-/issues/270544
 export const throughputChartData = {
-  May_2020: { count: 2, __typename: 'MergeRequestConnection' },
-  Jun_2020: { count: 4, __typename: 'MergeRequestConnection' },
-  Jul_2020: { count: 3, __typename: 'MergeRequestConnection' },
+  May_2020: { count: 2, totalTimeToMerge: 1234567, __typename: 'MergeRequestConnection' },
+  Jun_2020: { count: 4, totalTimeToMerge: 2345678, __typename: 'MergeRequestConnection' },
+  Jul_2020: { count: 3, totalTimeToMerge: 3456789, __typename: 'MergeRequestConnection' },
   __typename: 'Project',
 };
 
@@ -32,6 +32,12 @@ export const formattedThroughputChartData = [
   },
 ];
 
+export const formattedMttmData = {
+  title: 'Mean time to merge',
+  value: '9',
+  unit: 'days',
+};
+
 export const expectedMonthData = [
   {
     year: 2020,
@@ -67,6 +73,7 @@ export const throughputChartQuery = `query ($fullPath: ID!, $labels: [String!],
       targetBranches: $targetBranches
     ) {
       count
+      totalTimeToMerge
     }
     Jun_2020: mergeRequests(
       first: 0
@@ -80,6 +87,7 @@ export const throughputChartQuery = `query ($fullPath: ID!, $labels: [String!],
       targetBranches: $targetBranches
     ) {
       count
+      totalTimeToMerge
     }
     Jul_2020: mergeRequests(
       first: 0
@@ -93,6 +101,7 @@ export const throughputChartQuery = `query ($fullPath: ID!, $labels: [String!],
       targetBranches: $targetBranches
     ) {
       count
+      totalTimeToMerge
     }
   }
 }
@@ -148,3 +157,16 @@ export const throughputTableData = [
     },
   },
 ];
+
+export const stats = [
+  {
+    title: 'Mean time to merge',
+    unit: 'days',
+    value: '10',
+  },
+  {
+    title: 'MRs per engineer',
+    unit: 'MRs per engineer (per month)',
+    value: '23',
+  },
+];

ee/spec/frontend/analytics/merge_request_analytics/utils_spec.js

 import * as utils from 'ee/analytics/merge_request_analytics/utils';
 import { useFakeDate } from 'helpers/fake_date';
-import { expectedMonthData, throughputChartData, formattedThroughputChartData } from './mock_data';
+import {
+  expectedMonthData,
+  throughputChartData,
+  formattedThroughputChartData,
+  formattedMttmData,
+} from './mock_data';
 
 describe('computeMonthRangeData', () => {
   const start = new Date('2020-05-17T00:00:00.000Z');
@@ -33,6 +38,14 @@ describe('formatThroughputChartData', () => {
   });
 });
 
+describe('computeMttmData', () => {
+  it('returns the data as expected', () => {
+    const mttmData = utils.computeMttmData(throughputChartData);
+
+    expect(mttmData).toStrictEqual(formattedMttmData);
+  });
+});
+
 describe('parseAndValidateDates', () => {
   useFakeDate('2021-01-21');
 

locale/gitlab.pot

@@ -17550,6 +17550,9 @@ msgstr ""
 msgid "May"
 msgstr ""
 
+msgid "Mean time to merge"
+msgstr ""
+
 msgid "Measured in bytes of code. Excludes generated and vendored code."
 msgstr ""
 
@@ -33593,6 +33596,9 @@ msgid_plural "days"
 msgstr[0] ""
 msgstr[1] ""
 
+msgid "days"
+msgstr ""
+
 msgid "default branch"
 msgstr ""
 

qa/qa/ee/page/group/menu.rb

@@ -53,6 +53,12 @@ module QA
               view 'ee/app/views/layouts/nav/sidebar/_group_iterations_link.html.haml' do
                 element :group_iterations_link
               end
+
+              view 'ee/app/views/groups/sidebar/_packages.html.haml' do
+                element :group_packages_item
+                element :group_packages_link
+                element :group_packages_submenu
+              end
             end
           end
 
@@ -140,6 +146,14 @@ module QA
             end
           end
 
+          def go_to_group_packages
+            hover_element(:group_packages_item) do
+              within_submenu(:group_packages_submenu) do
+                click_element(:group_packages_link)
+              end
+            end
+          end
+
           def click_group_wiki_link
             within_sidebar do
               click_element(:wiki_link)

qa/qa/specs/features/browser_ui/5_package/nuget_repository_spec.rb

@@ -13,6 +13,13 @@ module QA
         end
       end
 
+      let(:another_project) do
+        Resource::Project.fabricate_via_api! do |project|
+          project.name = 'nuget-package-install-project'
+          project.template_name = 'dotnetcore'
+        end
+      end
+
       let!(:runner) do
         Resource::Runner.fabricate! do |runner|
           runner.name = "qa-runner-#{Time.now.to_i}"
@@ -22,11 +29,21 @@ module QA
         end
       end
 
+      let!(:another_runner) do
+        Resource::Runner.fabricate! do |runner|
+          runner.name = "qa-runner-#{Time.now.to_i}"
+          runner.tags = ["runner-for-#{another_project.name}"]
+          runner.executor = :docker
+          runner.project = another_project
+        end
+      end
+
       after do
         runner.remove_via_api!
+        another_runner.remove_via_api!
       end
 
-      it 'publishes a nuget package and deletes it', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/1073' do
+      it 'publishes a nuget package at the project level, installs and deletes it at the group level', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/1073' do
         Flow::Login.sign_in
 
         Resource::Repository::Commit.fabricate_via_api! do |commit|
@@ -37,23 +54,23 @@ module QA
                 {
                     file_path: '.gitlab-ci.yml',
                     content: <<~YAML
-                    image: mcr.microsoft.com/dotnet/core/sdk:3.1
-
-                    stages:
-                      - deploy
-
-                    deploy:
-                      stage: deploy
-                      script:
-                        - dotnet restore -p:Configuration=Release
-                        - dotnet build -c Release
-                        - dotnet pack -c Release
-                        - dotnet nuget add source "$CI_SERVER_URL/api/v4/projects/$CI_PROJECT_ID/packages/nuget/index.json" --name gitlab --username gitlab-ci-token --password $CI_JOB_TOKEN --store-password-in-clear-text
-                        - dotnet nuget push "bin/Release/*.nupkg" --source gitlab
-                      only:
-                        - "#{project.default_branch}"
-                      tags:
-                        - "runner-for-#{project.name}"
+                      image: mcr.microsoft.com/dotnet/core/sdk:3.1
+
+                      stages:
+                        - deploy
+
+                      deploy:
+                        stage: deploy
+                        script:
+                          - dotnet restore -p:Configuration=Release
+                          - dotnet build -c Release
+                          - dotnet pack -c Release
+                          - dotnet nuget add source "$CI_SERVER_URL/api/v4/projects/$CI_PROJECT_ID/packages/nuget/index.json" --name gitlab --username gitlab-ci-token --password $CI_JOB_TOKEN --store-password-in-clear-text
+                          - dotnet nuget push "bin/Release/*.nupkg" --source gitlab
+                        only:
+                          - "#{project.default_branch}"
+                        tags:
+                          - "runner-for-#{project.name}"
                     YAML
                 }
             ]
@@ -71,7 +88,67 @@ module QA
           expect(job).to be_successful(timeout: 800)
         end
 
-        Page::Project::Menu.perform(&:click_packages_link)
+        another_project.visit!
+
+        Resource::Repository::Commit.fabricate_via_api! do |commit|
+          commit.project = another_project
+          commit.commit_message = 'Add new csproj file'
+          commit.add_files(
+            [
+                {
+                    file_path: 'otherdotnet.csproj',
+                    content: <<~EOF
+                        <Project Sdk="Microsoft.NET.Sdk">
+
+                          <PropertyGroup>
+                            <OutputType>Exe</OutputType>
+                            <TargetFramework>netcoreapp3.1</TargetFramework>
+                          </PropertyGroup>
+
+                        </Project>
+                    EOF
+                }
+            ]
+          )
+          commit.update_files(
+            [
+                {
+                    file_path: '.gitlab-ci.yml',
+                    content: <<~YAML
+                        image: mcr.microsoft.com/dotnet/core/sdk:3.1
+
+                        stages:
+                          - install
+
+                        install:
+                          stage: install
+                          script:
+                           - dotnet nuget locals all --clear
+                           - dotnet nuget add source "$CI_SERVER_URL/api/v4/groups/#{another_project.group.id}/-/packages/nuget/index.json" --name gitlab --username gitlab-ci-token --password $CI_JOB_TOKEN --store-password-in-clear-text
+                           - "dotnet add otherdotnet.csproj package #{package_name} --version 1.0.0"
+                          only:
+                            - "#{another_project.default_branch}"
+                          tags:
+                            - "runner-for-#{another_project.name}"
+                    YAML
+                }
+            ]
+          )
+        end
+
+        Flow::Pipeline.visit_latest_pipeline
+
+        Page::Project::Pipeline::Show.perform do |pipeline|
+          pipeline.click_job('install')
+        end
+
+        Page::Project::Job::Show.perform do |job|
+          expect(job).to be_successful(timeout: 800)
+        end
+
+        project.group.sandbox.visit!
+
+        Page::Group::Menu.perform(&:go_to_group_packages)
 
         Page::Project::Packages::Index.perform do |index|
           expect(index).to have_package(package_name)

spec/controllers/projects/merge_requests/diffs_controller_spec.rb

@@ -226,11 +226,7 @@ RSpec.describe Projects::MergeRequests::DiffsController do
         let(:diffable_merge_ref) { true }
 
         it 'compares diffs with the head' do
-          MergeRequests::MergeToRefService.new(project, merge_request.author).execute(merge_request)
-
-          expect(CompareService).to receive(:new).with(
-            project, merge_request.merge_ref_head.sha
-          ).and_call_original
+          create(:merge_request_diff, :merge_head, merge_request: merge_request)
 
           go(diff_head: true)
 
@@ -242,8 +238,6 @@ RSpec.describe Projects::MergeRequests::DiffsController do
         let(:diffable_merge_ref) { false }
 
         it 'compares diffs with the base' do
-          expect(CompareService).not_to receive(:new)
-
           go(diff_head: true)
 
           expect(response).to have_gitlab_http_status(:ok)

spec/factories/merge_request_diffs.rb

@@ -10,12 +10,18 @@ FactoryBot.define do
     head_commit_sha { Digest::SHA1.hexdigest(SecureRandom.hex) }
     start_commit_sha { Digest::SHA1.hexdigest(SecureRandom.hex) }
 
+    diff_type { :regular }
+
     trait :external do
       external_diff { fixture_file_upload("spec/fixtures/doc_sample.txt", "plain/txt") }
       stored_externally { true }
       importing { true } # this avoids setting the state to 'empty'
     end
 
+    trait :merge_head do
+      diff_type { :merge_head }
+    end
+
     factory :external_merge_request_diff, traits: [:external]
   end
 end

spec/lib/gitlab/import_export/all_models.yml

@@ -146,6 +146,7 @@ merge_requests:
 - merge_user
 - merge_request_diffs
 - merge_request_diff
+- merge_head_diff
 - merge_request_context_commits
 - merge_request_context_commit_diff_files
 - events

spec/lib/gitlab/import_export/safe_model_attributes.yml

@@ -220,6 +220,7 @@ MergeRequestDiff:
 - commits_count
 - files_count
 - sorted
+- diff_type
 MergeRequestDiffCommit:
 - merge_request_diff_id
 - relative_order

spec/models/merge_request_diff_spec.rb

@@ -16,6 +16,8 @@ RSpec.describe MergeRequestDiff do
   describe 'validations' do
     subject { diff_with_commits }
 
+    it { is_expected.not_to validate_uniqueness_of(:diff_type).scoped_to(:merge_request_id) }
+
     it 'checks sha format of base_commit_sha, head_commit_sha and start_commit_sha' do
       subject.base_commit_sha = subject.head_commit_sha = subject.start_commit_sha = 'foobar'
 
@@ -23,6 +25,24 @@ RSpec.describe MergeRequestDiff do
       expect(subject.errors.count).to eq 3
       expect(subject.errors).to all(include('is not a valid SHA'))
     end
+
+    it 'does not validate uniqueness by default' do
+      expect(build(:merge_request_diff, merge_request: subject.merge_request)).to be_valid
+    end
+
+    context 'when merge request diff is a merge_head type' do
+      it 'is valid' do
+        expect(build(:merge_request_diff, :merge_head, merge_request: subject.merge_request)).to be_valid
+      end
+
+      context 'when merge_head diff exists' do
+        let(:existing_merge_head_diff) { create(:merge_request_diff, :merge_head) }
+
+        it 'validates uniqueness' do
+          expect(build(:merge_request_diff, :merge_head, merge_request: existing_merge_head_diff.merge_request)).not_to be_valid
+        end
+      end
+    end
   end
 
   describe 'create new record' do
@@ -35,6 +55,26 @@ RSpec.describe MergeRequestDiff do
     it { expect(subject.head_commit_sha).to eq('b83d6e391c22777fca1ed3012fce84f633d7fed0') }
     it { expect(subject.base_commit_sha).to eq('ae73cb07c9eeaf35924a10f713b364d32b2dd34f') }
     it { expect(subject.start_commit_sha).to eq('0b4bc9a49b562e85de7cc9e834518ea6828729b9') }
+
+    context 'when diff_type is merge_head' do
+      let_it_be(:merge_request) { create(:merge_request) }
+
+      let_it_be(:merge_head) do
+        MergeRequests::MergeToRefService
+          .new(merge_request.project, merge_request.author)
+          .execute(merge_request)
+
+        merge_request.create_merge_head_diff
+      end
+
+      it { expect(merge_head).to be_valid }
+      it { expect(merge_head).to be_persisted }
+      it { expect(merge_head.commits.count).to eq(30) }
+      it { expect(merge_head.diffs.count).to eq(20) }
+      it { expect(merge_head.head_commit_sha).to eq(merge_request.merge_ref_head.diff_refs.head_sha) }
+      it { expect(merge_head.base_commit_sha).to eq(merge_request.merge_ref_head.diff_refs.base_sha) }
+      it { expect(merge_head.start_commit_sha).to eq(merge_request.target_branch_sha) }
+    end
   end
 
   describe '.by_commit_sha' do
@@ -63,6 +103,7 @@ RSpec.describe MergeRequestDiff do
     let_it_be(:merge_request) { create(:merge_request) }
     let_it_be(:outdated) { merge_request.merge_request_diff }
     let_it_be(:latest) { merge_request.create_merge_request_diff }
+    let_it_be(:merge_head) { merge_request.create_merge_head_diff }
 
     let_it_be(:closed_mr) { create(:merge_request, :closed_last_month) }
     let(:closed) { closed_mr.merge_request_diff }
@@ -103,14 +144,14 @@ RSpec.describe MergeRequestDiff do
         stub_external_diffs_setting(enabled: true)
       end
 
-      it { is_expected.to contain_exactly(outdated.id, latest.id, closed.id, merged.id, closed_recently.id, merged_recently.id) }
+      it { is_expected.to contain_exactly(outdated.id, latest.id, closed.id, merged.id, closed_recently.id, merged_recently.id, merge_head.id) }
 
       it 'ignores diffs with 0 files' do
         MergeRequestDiffFile.where(merge_request_diff_id: [closed_recently.id, merged_recently.id]).delete_all
         closed_recently.update!(files_count: 0)
         merged_recently.update!(files_count: 0)
 
-        is_expected.to contain_exactly(outdated.id, latest.id, closed.id, merged.id)
+        is_expected.to contain_exactly(outdated.id, latest.id, closed.id, merged.id, merge_head.id)
       end
     end
 

spec/models/merge_request_spec.rb

@@ -491,6 +491,7 @@ RSpec.describe MergeRequest, factory_default: :keep do
 
       create(:merge_request, params).tap do |mr|
         diffs.times { mr.merge_request_diffs.create }
+        mr.create_merge_head_diff
       end
     end
 
@@ -4379,37 +4380,41 @@ RSpec.describe MergeRequest, factory_default: :keep do
   end
 
   describe '#diffable_merge_ref?' do
+    let(:merge_request) { create(:merge_request) }
+
     context 'merge request can be merged' do
-      context 'merge_to_ref is not calculated' do
+      context 'merge_head diff is not created' do
         it 'returns true' do
-          expect(subject.diffable_merge_ref?).to eq(false)
+          expect(merge_request.diffable_merge_ref?).to eq(false)
         end
       end
 
-      context 'merge_to_ref is calculated' do
+      context 'merge_head diff is created' do
         before do
-          MergeRequests::MergeToRefService.new(subject.project, subject.author).execute(subject)
+          create(:merge_request_diff, :merge_head, merge_request: merge_request)
         end
 
         it 'returns true' do
-          expect(subject.diffable_merge_ref?).to eq(true)
+          expect(merge_request.diffable_merge_ref?).to eq(true)
         end
 
         context 'merge request is merged' do
-          subject { build_stubbed(:merge_request, :merged, project: project) }
+          before do
+            merge_request.mark_as_merged!
+          end
 
           it 'returns false' do
-            expect(subject.diffable_merge_ref?).to eq(false)
+            expect(merge_request.diffable_merge_ref?).to eq(false)
           end
         end
 
         context 'merge request cannot be merged' do
           before do
-            subject.mark_as_unchecked!
+            merge_request.mark_as_unchecked!
           end
 
           it 'returns false' do
-            expect(subject.diffable_merge_ref?).to eq(true)
+            expect(merge_request.diffable_merge_ref?).to eq(true)
           end
 
           context 'display_merge_conflicts_in_diff is disabled' do
@@ -4418,7 +4423,7 @@ RSpec.describe MergeRequest, factory_default: :keep do
             end
 
             it 'returns false' do
-              expect(subject.diffable_merge_ref?).to eq(false)
+              expect(merge_request.diffable_merge_ref?).to eq(false)
             end
           end
         end

spec/services/merge_requests/delete_non_latest_diffs_service_spec.rb

@@ -12,6 +12,8 @@ RSpec.describe MergeRequests::DeleteNonLatestDiffsService, :clean_gitlab_redis_s
       stub_const("#{described_class.name}::BATCH_SIZE", 2)
 
       3.times { merge_request.create_merge_request_diff }
+      merge_request.create_merge_head_diff
+      merge_request.reset
     end
 
     it 'schedules non-latest merge request diffs removal' do

spec/services/merge_requests/mergeability_check_service_spec.rb

@@ -33,6 +33,14 @@ RSpec.describe MergeRequests::MergeabilityCheckService, :clean_gitlab_redis_shar
       expect(merge_request.merge_status).to eq('can_be_merged')
     end
 
+    it 'reloads merge head diff' do
+      expect_next_instance_of(MergeRequests::ReloadMergeHeadDiffService) do |service|
+        expect(service).to receive(:execute)
+      end
+
+      subject
+    end
+
     it 'update diff discussion positions' do
       expect_next_instance_of(Discussions::CaptureDiffNotePositionsService) do |service|
         expect(service).to receive(:execute)
@@ -142,7 +150,11 @@ RSpec.describe MergeRequests::MergeabilityCheckService, :clean_gitlab_redis_shar
       end
 
       it 'resets one merge request upon execution' do
-        expect_any_instance_of(MergeRequest).to receive(:reset).once
+        expect_next_instance_of(MergeRequests::ReloadMergeHeadDiffService) do |svc|
+          expect(svc).to receive(:execute).and_return(status: :success)
+        end
+
+        expect_any_instance_of(MergeRequest).to receive(:reset).once.and_call_original
 
         execute_within_threads(amount: 2)
       end
@@ -266,6 +278,14 @@ RSpec.describe MergeRequests::MergeabilityCheckService, :clean_gitlab_redis_shar
 
       it_behaves_like 'unmergeable merge request'
 
+      it 'reloads merge head diff' do
+        expect_next_instance_of(MergeRequests::ReloadMergeHeadDiffService) do |service|
+          expect(service).to receive(:execute)
+        end
+
+        subject
+      end
+
       it 'returns ServiceResponse.error' do
         result = subject
 
@@ -329,6 +349,12 @@ RSpec.describe MergeRequests::MergeabilityCheckService, :clean_gitlab_redis_shar
 
           subject
         end
+
+        it 'does not reload merge head diff' do
+          expect(MergeRequests::ReloadMergeHeadDiffService).not_to receive(:new)
+
+          subject
+        end
       end
     end
 

spec/services/merge_requests/reload_merge_head_diff_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe MergeRequests::ReloadMergeHeadDiffService do
+  let(:merge_request) { create(:merge_request) }
+
+  subject { described_class.new(merge_request).execute }
+
+  describe '#execute' do
+    before do
+      MergeRequests::MergeToRefService
+        .new(merge_request.project, merge_request.author)
+        .execute(merge_request)
+    end
+
+    it 'creates a merge head diff' do
+      expect(subject[:status]).to eq(:success)
+      expect(merge_request.reload.merge_head_diff).to be_present
+    end
+
+    context 'when merge ref head is not present' do
+      before do
+        allow(merge_request).to receive(:merge_ref_head).and_return(nil)
+      end
+
+      it 'returns error' do
+        expect(subject[:status]).to eq(:error)
+      end
+    end
+
+    context 'when failed to create merge head diff' do
+      before do
+        allow(merge_request).to receive(:create_merge_head_diff!).and_raise('fail')
+      end
+
+      it 'returns error' do
+        expect(subject[:status]).to eq(:error)
+      end
+    end
+
+    context 'when there is existing merge head diff' do
+      let!(:existing_merge_head_diff) { create(:merge_request_diff, :merge_head, merge_request: merge_request) }
+
+      it 'recreates merge head diff' do
+        expect(subject[:status]).to eq(:success)
+        expect(merge_request.reload.merge_head_diff).not_to eq(existing_merge_head_diff)
+      end
+    end
+
+    context 'when default_merge_ref_for_diffs feature flag is disabled' do
+      before do
+        stub_feature_flags(default_merge_ref_for_diffs: false)
+      end
+
+      it 'returns error' do
+        expect(subject[:status]).to eq(:error)
+      end
+    end
+  end
+end