Merge branch 'zj-use-project-finder-pipelines-api' into 'master'

Use PipelinesFinder in Pipelines API

## What does this MR do?

Sort output for the API endpoint, and uses the PipelinesFinder there.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #21566

See merge request !6094

CHANGELOG

@@ -36,6 +36,7 @@ v 8.12.0 (unreleased)
   - Add Sentry logging to API calls
   - Add BroadcastMessage API
   - Use 'git update-ref' for safer web commits !6130
+  - Sort pipelines requested through the API
   - Automatically expand hidden discussions when accessed by a permalink !5585 (Mike Greiling)
   - Remove unused mixins (ClemMakesApps)
   - Add search to all issue board lists

app/controllers/projects/pipelines_controller.rb

@@ -7,11 +7,10 @@ class Projects::PipelinesController < Projects::ApplicationController
   def index
     @scope = params[:scope]
-    all_pipelines = project.pipelines
-    @pipelines_count = all_pipelines.count
-    @running_or_pending_count = all_pipelines.running_or_pending.count
-    @pipelines = PipelinesFinder.new(project).execute(all_pipelines, @scope)
-    @pipelines = @pipelines.order(id: :desc).page(params[:page]).per(30)
+    @pipelines = PipelinesFinder.new(project).execute(scope: @scope).page(params[:page]).per(30)
+
+    @running_or_pending_count = PipelinesFinder.new(project).execute(scope: 'running').count
+    @pipelines_count = PipelinesFinder.new(project).execute.count
   end
   def new

app/finders/pipelines_finder.rb

 class PipelinesFinder
-  attr_reader :project
+  attr_reader :project, :pipelines
   def initialize(project)
     @project = project
+    @pipelines = project.pipelines
   end
-  def execute(pipelines, scope)
-    case scope
-    when 'running'
-      pipelines.running_or_pending
-    when 'branches'
-      from_ids(pipelines, ids_for_ref(pipelines, branches))
-    when 'tags'
-      from_ids(pipelines, ids_for_ref(pipelines, tags))
-    else
-      pipelines
-    end
+  def execute(scope: nil)
+    scoped_pipelines =
+      case scope
+      when 'running'
+        pipelines.running_or_pending
+      when 'branches'
+        from_ids(ids_for_ref(branches))
+      when 'tags'
+        from_ids(ids_for_ref(tags))
+      else
+        pipelines
+      end
+
+    scoped_pipelines.order(id: :desc)
   end
   private
-  def ids_for_ref(pipelines, refs)
+  def ids_for_ref(refs)
     pipelines.where(ref: refs).group(:ref).select('max(id)')
   end
-  def from_ids(pipelines, ids)
+  def from_ids(ids)
     pipelines.unscoped.where(id: ids)
   end

lib/api/pipelines.rb

@@ -13,11 +13,14 @@ module API
       params do
         optional :page,     type: Integer, desc: 'Page number of the current request'
         optional :per_page, type: Integer, desc: 'Number of items per page'
+        optional :scope,    type: String, values: ['running', 'branches', 'tags'],
+                            desc: 'Either running, branches, or tags'
       end
       get ':id/pipelines' do
         authorize! :read_pipeline, user_project
-        present paginate(user_project.pipelines), with: Entities::Pipeline
+        pipelines = PipelinesFinder.new(user_project).execute(scope: params[:scope])
+        present paginate(pipelines), with: Entities::Pipeline
       end
       desc 'Gets a specific pipeline for the project' do

spec/finders/pipelines_finder_spec.rb

+require 'spec_helper'
+
+describe PipelinesFinder do
+  let(:project) { create(:project) }
+
+  let!(:tag_pipeline)    { create(:ci_pipeline, project: project, ref: 'v1.0.0') }
+  let!(:branch_pipeline) { create(:ci_pipeline, project: project) }
+
+  subject { described_class.new(project).execute(params) }
+
+  describe "#execute" do
+    context 'when a scope is passed' do
+      context 'when scope is nil' do
+        let(:params) { { scope: nil } }
+
+        it 'selects all pipelines' do
+          expect(subject.count).to be 2
+          expect(subject).to include tag_pipeline
+          expect(subject).to include branch_pipeline
+        end
+      end
+
+      context 'when selecting branches' do
+        let(:params) { { scope: 'branches' } }
+
+        it 'excludes tags' do
+          expect(subject).not_to include tag_pipeline
+          expect(subject).to     include branch_pipeline
+        end
+      end
+
+      context 'when selecting tags' do
+        let(:params) { { scope: 'tags' } }
+
+        it 'excludes branches' do
+          expect(subject).to     include tag_pipeline
+          expect(subject).not_to include branch_pipeline
+        end
+      end
+    end
+
+    # Scoping to running will speed up the test as it doesn't hit the FS
+    let(:params) { { scope: 'running' } }
+
+    it 'orders in descending order on ID' do
+      create(:ci_pipeline, project: project, ref: 'feature')
+
+      expect(subject.map(&:id)).to eq [3, 2, 1]
+    end
+  end
+end