Display related merge requests in commit detail page

7 files changed, 104 insertions, 2 deletions

diff --git a/app/assets/javascripts/commit_merge_requests.js b/app/assets/javascripts/commit_merge_requests.js
new file mode 100644
index 00000000000..f76c9b7e690
--- /dev/null
+++ b/app/assets/javascripts/commit_merge_requests.js
@@ -0,0 +1,73 @@
+/* global Flash */
+
+import axios from './lib/utils/axios_utils';
+import { n__, s__ } from './locale';
+
+export function getHeaderText(childElementCount, mergeRequestCount) {
+  if (childElementCount === 0) {
+    return `${mergeRequestCount} ${n__('merge request', 'merge requests', mergeRequestCount)}`;
+  }
+  return ',';
+}
+
+export function createHeader(childElementCount, mergeRequestCount) {
+  const headerText = getHeaderText(childElementCount, mergeRequestCount);
+
+  return $('<span />', {
+    class: 'append-right-5',
+    text: headerText,
+  });
+}
+
+export function createLink(mergeRequest) {
+  return $('<a />', {
+    class: 'append-right-5',
+    href: mergeRequest.path,
+    text: `!${mergeRequest.iid}`,
+  });
+}
+
+export function createTitle(mergeRequest) {
+  return $('<span />', {
+    text: mergeRequest.title,
+  });
+}
+
+export function createItem(mergeRequest) {
+  const $item = $('<span />');
+  const $link = createLink(mergeRequest);
+  const $title = createTitle(mergeRequest);
+  $item.append($link);
+  $item.append($title);
+
+  return $item;
+}
+
+export function createContent(mergeRequests) {
+  const $content = $('<span />');
+
+  if (mergeRequests.length === 0) {
+    $content.text(s__('Commits|No related merge requests found'));
+  } else {
+    mergeRequests.forEach((mergeRequest) => {
+      const $header = createHeader($content.children().length, mergeRequests.length);
+      const $item = createItem(mergeRequest);
+      $content.append($header);
+      $content.append($item);
+    });
+  }
+
+  return $content;
+}
+
+export function fetchCommitMergeRequests() {
+  const $container = $('.merge-requests');
+
+  axios.get($container.data('projectCommitPath'))
+    .then((response) => {
+      const $content = createContent(response.data);
+
+      $container.html($content);
+    })
+    .catch(() => Flash(s__('Commits|An error occurred while fetching merge requests data.')));
+}
diff --git a/app/assets/javascripts/dispatcher.js b/app/assets/javascripts/dispatcher.js
index 64fb8aaeb7a..04b90035bcb 100644
--- a/app/assets/javascripts/dispatcher.js
+++ b/app/assets/javascripts/dispatcher.js
@@ -68,6 +68,7 @@ import Diff from './diff';
 import ProjectLabelSubscription from './project_label_subscription';
 import SearchAutocomplete from './search_autocomplete';
 import Activities from './activities';
+import { fetchCommitMergeRequests } from './commit_merge_requests';
 
 (function() {
   var Dispatcher;
@@ -311,6 +312,7 @@ import Activities from './activities';
           const stickyBarPaddingTop = 16;
           initChangesDropdown(document.querySelector('.navbar-gitlab').offsetHeight - stickyBarPaddingTop);
           $('.commit-info.branches').load(document.querySelector('.js-commit-box').dataset.commitPath);
+          fetchCommitMergeRequests();
           break;
         case 'projects:commit:pipelines':
           new MiniPipelineGraph({
diff --git a/app/controllers/projects/commit_controller.rb b/app/controllers/projects/commit_controller.rb
index 2e7344b1cad..effb484ef0f 100644
--- a/app/controllers/projects/commit_controller.rb
+++ b/app/controllers/projects/commit_controller.rb
@@ -12,7 +12,7 @@ class Projects::CommitController < Projects::ApplicationController
   before_action :authorize_download_code!
   before_action :authorize_read_pipeline!, only: [:pipelines]
   before_action :commit
-  before_action :define_commit_vars, only: [:show, :diff_for_path, :pipelines]
+  before_action :define_commit_vars, only: [:show, :diff_for_path, :pipelines, :merge_requests]
   before_action :define_note_vars, only: [:show, :diff_for_path]
   before_action :authorize_edit_tree!, only: [:revert, :cherry_pick]
 
@@ -52,6 +52,18 @@ class Projects::CommitController < Projects::ApplicationController
     end
   end
 
+  def merge_requests
+    @merge_requests = @commit.merge_requests.map do |mr|
+      { iid: mr.iid, path: merge_request_path(mr), title: mr.title }
+    end
+
+    respond_to do |format|
+      format.json do
+        render json: @merge_requests.to_json
+      end
+    end
+  end
+
   def branches
     # branch_names_contains/tag_names_contains can take a long time when there are thousands of
     # branches/tags - each `git branch --contains xxx` request can consume a cpu core.
diff --git a/app/models/commit.rb b/app/models/commit.rb
index ede8ad301e4..21904c87f01 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -238,6 +238,10 @@ class Commit
     notes.includes(:author)
   end
 
+  def merge_requests
+    @merge_requests ||= project.merge_requests.by_commit_sha(sha)
+  end
+
   def method_missing(method, *args, &block)
     @raw.__send__(method, *args, &block) # rubocop:disable GitlabSecurity/PublicSend
   end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index b7762a5f281..8028ff3875b 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -140,7 +140,9 @@ class MergeRequest < ActiveRecord::Base
   scope :merged, -> { with_state(:merged) }
   scope :closed_and_merged, -> { with_states(:closed, :merged) }
   scope :from_source_branches, ->(branches) { where(source_branch: branches) }
-
+  scope :by_commit_sha, ->(sha) do
+    where('EXISTS (?)', MergeRequestDiff.select(1).where('merge_requests.latest_merge_request_diff_id = merge_request_diffs.id').by_commit_sha(sha)).reorder(nil)
+  end
   scope :join_project, -> { joins(:target_project) }
   scope :references_project, -> { references(:target_project) }
   scope :assigned, -> { where("assignee_id IS NOT NULL") }
diff --git a/app/models/merge_request_diff.rb b/app/models/merge_request_diff.rb
index afab72930c1..69a846da9be 100644
--- a/app/models/merge_request_diff.rb
+++ b/app/models/merge_request_diff.rb
@@ -28,6 +28,9 @@ class MergeRequestDiff < ActiveRecord::Base
   end
 
   scope :viewable, -> { without_state(:empty) }
+  scope :by_commit_sha, ->(sha) do
+    joins(:merge_request_diff_commits).where(merge_request_diff_commits: { sha: sha }).reorder(nil)
+  end
 
   scope :recent, -> { order(id: :desc).limit(100) }
 
diff --git a/app/views/projects/commit/_commit_box.html.haml b/app/views/projects/commit/_commit_box.html.haml
index 09934c09865..461129a3e0e 100644
--- a/app/views/projects/commit/_commit_box.html.haml
+++ b/app/views/projects/commit/_commit_box.html.haml
@@ -64,6 +64,12 @@
     .commit-info.branches
       %i.fa.fa-spinner.fa-spin
 
+  .well-segment.merge-request-info
+    .icon-container
+      = custom_icon('mr_bold')
+    %span.commit-info.merge-requests{ 'data-project-commit-path' => merge_requests_project_commit_path(@project, @commit.id, format: :json) }
+      = icon('spinner spin')
+
   - if @commit.last_pipeline
     - last_pipeline = @commit.last_pipeline
     .well-segment.pipeline-info