Merge branch 'cross-reference-mr-on-issues' into 'master'

Show merge requests which close current issue

Closes #2903

### What does this MR do
If an issue is to be closed by a merge request the current user has access to, this will be displayed when the user looks at the issue.

![Screenshot_from_2015-10-12_12-10-37](https://gitlab.com/zj/gitlab-ce/uploads/52e429704e73067b24b69801f13ad7bc/Screenshot_from_2015-10-12_12-10-37.png)

/cc @DouweM

See merge request !1569

CHANGELOG

@@ -9,6 +9,7 @@ v 8.1.0 (unreleased)
   - Fix nonatomic database update potentially causing project star counts to go negative (Stan Hu)
   - Fix error preventing displaying of commit data for a directory with a leading dot (Stan Hu)
   - Speed up load times of issue detail pages by roughly 1.5x
+  - If a merge request is to close an issue, show this on the issue page (Zeger-Jan van de Weg)
   - Add a system note and update relevant merge requests when a branch is deleted or re-added (Stan Hu)
   - Make diff file view easier to use on mobile screens (Stan Hu)
   - Improved performance of finding users by username or Email address

app/assets/stylesheets/pages/issues.scss

@@ -132,6 +132,11 @@ form.edit-issue {
   }
 }
 
+.issue-closed-by-widget {
+  padding: 16px 0;
+  margin: 0px;
+}
+
 .issue-form .select2-container {
   width: 250px !important;
 }

app/controllers/projects/issues_controller.rb

@@ -14,6 +14,9 @@ class Projects::IssuesController < Projects::ApplicationController
   # Allow issues bulk update
   before_action :authorize_admin_issues!, only: [:bulk_update]
 
+  # Cross-reference merge requests
+  before_action :closed_by_merge_requests, only: [:show]
+
   respond_to :html
 
   def index
@@ -112,6 +115,10 @@ class Projects::IssuesController < Projects::ApplicationController
     render nothing: true
   end
 
+  def closed_by_merge_requests
+    @closed_by_merge_requests ||= @issue.closed_by_merge_requests(current_user)
+  end
+
   protected
 
   def issue

app/helpers/issues_helper.rb

@@ -83,6 +83,10 @@ module IssuesHelper
     end
   end
 
+  def merge_requests_sentence(merge_requests)
+    merge_requests.map(&:to_reference).to_sentence(last_word_connector: ', or ')
+  end
+
   # Required for Gitlab::Markdown::IssueReferenceFilter
   module_function :url_for_issue
 end

app/models/concerns/issuable.rb

@@ -85,6 +85,10 @@ module Issuable
     assignee_id_changed?
   end
 
+  def open?
+    opened? || reopened?
+  end
+
   #
   # Votes
   #

app/models/issue.rb

@@ -95,4 +95,14 @@ class Issue < ActiveRecord::Base
   def source_project
     project
   end
+
+  # From all notes on this issue, we'll select the system notes about linked
+  # merge requests. Of those, the MRs closing `self` are returned.
+  def closed_by_merge_requests(current_user = nil)
+    return [] unless open?
+
+    notes.system.flat_map do |note|
+      note.all_references(current_user).merge_requests
+    end.uniq.select { |mr| mr.open? && mr.closes_issue?(self) }
+  end
 end

app/models/merge_request.rb

@@ -222,10 +222,6 @@ class MergeRequest < ActiveRecord::Base
     self.target_project.events.where(target_id: self.id, target_type: "MergeRequest", action: Event::CLOSED).last
   end
 
-  def open?
-    opened? || reopened?
-  end
-
   def work_in_progress?
     !!(title =~ /\A\[?WIP\]?:? /i)
   end
@@ -294,6 +290,10 @@ class MergeRequest < ActiveRecord::Base
     target_project
   end
 
+  def closes_issue?(issue)
+    closes_issues.include?(issue)
+  end
+
   # Return the set of issues that will be closed if this merge request is accepted.
   def closes_issues(current_user = self.author)
     if target_branch == project.default_branch

app/views/projects/issues/_closed_by_box.html.haml

+.issue-closed-by-widget
+  = icon('check')
+  This issue will be closed automatically when merge request #{gfm(merge_requests_sentence(@closed_by_merge_requests.sort))} is accepted.

app/views/projects/issues/show.html.haml

@@ -46,6 +46,7 @@
                 = markdown(@issue.description)
             %textarea.hidden.js-task-list-field
               = @issue.description
-
+  - if @closed_by_merge_requests.present?
+    = render 'projects/issues/closed_by_box'
   .issue-discussion
     = render 'projects/issues/discussion'

spec/helpers/issues_helper_spec.rb

@@ -117,4 +117,14 @@ describe IssuesHelper do
     end
   end
 
+  describe "#merge_requests_sentence" do
+    subject { merge_requests_sentence(merge_requests)}
+    let(:merge_requests) do
+      [ build(:merge_request, iid: 1), build(:merge_request, iid: 2),
+        build(:merge_request, iid: 3)]
+    end
+
+    it { is_expected.to eq("!1, !2, or !3") }
+  end
+
 end

spec/models/concerns/issuable_spec.rb

@@ -68,7 +68,6 @@ describe Issue, "Issuable" do
     end
   end
 
-
   describe "#to_hook_data" do
     let(:hook_data) { issue.to_hook_data(user) }
 

spec/models/issue_spec.rb

@@ -68,6 +68,43 @@ describe Issue do
     end
   end
 
+  describe '#closed_by_merge_requests' do
+    let(:project) { create(:project) }
+    let(:issue)   { create(:issue, project: project, state: "opened")}
+    let(:closed_issue) { build(:issue, project: project, state: "closed")}
+
+    let(:mr) do
+      opts = {
+        title: 'Awesome merge_request',
+        description: "Fixes #{issue.to_reference}",
+        source_branch: 'feature',
+        target_branch: 'master'
+      }
+      MergeRequests::CreateService.new(project, project.owner, opts).execute
+    end
+
+    let(:closed_mr) do
+      opts = {
+        title: 'Awesome merge_request 2',
+        description: "Fixes #{issue.to_reference}",
+        source_branch: 'feature',
+        target_branch: 'master',
+        state: 'closed'
+      }
+      MergeRequests::CreateService.new(project, project.owner, opts).execute
+    end
+
+    it 'returns the merge request to close this issue' do
+      allow(mr).to receive(:closes_issue?).with(issue).and_return(true)
+
+      expect(issue.closed_by_merge_requests).to eq([mr])
+    end
+
+    it "returns an empty array when the current issue is closed already" do
+      expect(closed_issue.closed_by_merge_requests).to eq([])
+    end
+  end
+
   it_behaves_like 'an editable mentionable' do
     subject { create(:issue) }