Initial implementation for real time job view

Added the needed keys and paths to a new entity, BuildDetailsEntity.
Not renaming BuildEntity to BuildBasicEntity on explicit request. Most
code now has test coverage, but not all. This will be added on later
commits on this branch.

Resolves gitlab-org/gitlab-ce#31397

app/controllers/projects/jobs_controller.rb

@@ -45,6 +45,17 @@ class Projects::JobsController < Projects::ApplicationController
     @builds = @project.pipelines.find_by_sha(@build.sha).builds.order('id DESC')
     @builds = @builds.where("id not in (?)", @build.id)
     @pipeline = @build.pipeline
+
+    respond_to do |format|
+      format.html
+      format.json do
+        Gitlab::PollingInterval.set_header(response, interval: 10_000)
+
+        render json: BuildSerializer
+          .new(project: @project, current_user: @current_user)
+          .represent_status(@build, {}, BuildDetailsEntity)
+      end
+    end
   end
 
   def trace

app/models/ci/build.rb

@@ -204,6 +204,8 @@ module Ci
     end
 
     def merge_request
+      @merge_request ||=
+        begin
           merge_requests = MergeRequest.includes(:merge_request_diff)
             .where(source_branch: ref,
                    source_project: pipeline.project)
@@ -213,6 +215,7 @@ module Ci
             merge_request.commits_sha.include?(pipeline.sha)
           end
         end
+    end
 
     def repo_url
       auth = "gitlab-ci-token:#{ensure_token!}@"

app/serializers/build_details_entity.rb

+class BuildDetailsEntity < BuildEntity
+  expose :coverage, :erased_at, :duration
+  expose :tag_list, as: :tags
+
+  expose :artifacts, using: BuildArtifactEntity
+  expose :runner, using: RunnerEntity
+  expose :pipeline, using: PipelineEntity
+
+  expose :merge_request_path do |build|
+    merge_request = build.merge_request
+    project = build.project
+
+    if merge_request.nil? || !can?(request.current_user, :read_merge_request, project)
+      nil
+    else
+      namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+  end
+
+  expose :new_issue_path do |build|
+    project = build.project
+
+    unless build.failed? && can?(request.current_user, :create_issue, project)
+      nil
+    else
+      new_namespace_project_issue_path(project.namespace, project)
+    end
+  end
+
+  expose :raw_path do |build|
+    project = build.project
+    raw_namespace_project_build_path(project.namespace, project, build)
+  end
+end

app/serializers/build_serializer.rb

 class BuildSerializer < BaseSerializer
   entity BuildEntity
 
-  def represent_status(resource)
+  def represent_status(resource, opts = {}, entity_class = nil)
     data = represent(resource, { only: [:status] })
     data.fetch(:status, {})
+
+    represent(resource, opts, entity_class)
   end
 end

app/serializers/runner_entity.rb

+class RunnerEntity < Grape::Entity
+  expose :id, :name, :description
+end

changelogs/unreleased/zj-job-view-goes-real-time.yml

+---
+title: Job details page update real time
+merge_request: 11651
+author:

lib/gitlab/etag_caching/router.rb

@@ -9,7 +9,9 @@ module Gitlab
       #   - Ending in `noteable/issue/<id>/notes` for the `issue_notes` route
       #   - Ending in `issues/id`/realtime_changes` for the `issue_title` route
       USED_IN_ROUTES = %w[noteable issue notes issues realtime_changes
-                          commit pipelines merge_requests new].freeze
+                          commit pipelines merge_requests builds
+                          new].freeze
+
       RESERVED_WORDS = Gitlab::PathRegex::ILLEGAL_PROJECT_PATH_WORDS - USED_IN_ROUTES
       RESERVED_WORDS_REGEX = Regexp.union(*RESERVED_WORDS.map(&Regexp.method(:escape)))
       ROUTES = [
@@ -40,6 +42,10 @@ module Gitlab
         Gitlab::EtagCaching::Router::Route.new(
           %r(^(?!.*(#{RESERVED_WORDS_REGEX})).*/pipelines/\d+\.json\z),
           'project_pipeline'
+        ),
+        Gitlab::EtagCaching::Router::Route.new(
+          %r(^(?!.*(#{RESERVED_WORDS_REGEX})).*/builds/\d+\.json\z),
+          'project_build'
         )
       ].freeze
 

spec/controllers/projects/jobs_controller_spec.rb

@@ -101,9 +101,10 @@ describe Projects::JobsController do
   end
 
   describe 'GET show' do
-    context 'when build exists' do
-      let!(:build) { create(:ci_build, pipeline: pipeline) }
+    let!(:build) { create(:ci_build, :failed, pipeline: pipeline) }
 
+    context 'when requesting HTML' do
+      context 'when build exists' do
         before do
           get_show(id: build.id)
         end
@@ -123,6 +124,27 @@ describe Projects::JobsController do
           expect(response).to have_http_status(:not_found)
         end
       end
+    end
+
+    context 'when requesting JSON' do
+      let(:merge_request) { create(:merge_request, source_project: project) }
+
+      before do
+        project.add_developer(user)
+        sign_in(user)
+
+        allow_any_instance_of(Ci::Build).to receive(:merge_request).and_return(merge_request)
+
+        get_show(id: build.id, format: :json)
+      end
+
+      it 'exposes needed information' do
+        expect(response).to have_http_status(:ok)
+        expect(json_response['new_issue_path']).to end_with('/issues/new')
+        expect(json_response['raw_path']).to match(/builds\/\d+\/raw\z/)
+        expect(json_response['merge_request_path']).to match(/merge_requests\/\d+\z/)
+      end
+    end
 
     def get_show(**extra_params)
       params = {

spec/lib/gitlab/etag_caching/router_spec.rb

@@ -67,6 +67,17 @@ describe Gitlab::EtagCaching::Router do
     expect(result.name).to eq 'merge_request_pipelines'
   end
 
+  it 'matches build endpoint' do
+    env = build_env(
+      '/my-group/my-project/builds/234.json'
+    )
+
+    result = described_class.match(env)
+
+    expect(result).to be_present
+    expect(result.name).to eq 'project_build'
+  end
+
   it 'does not match blob with confusing name' do
     env = build_env(
       '/my-group/my-project/blob/master/pipelines.json'

spec/serializers/build_details_entity_spec.rb

+require 'spec_helper'
+
+describe BuildDetailsEntity do
+  it 'inherits from BuildEntity' do
+    expect(described_class).to be < BuildEntity
+  end
+
+  describe '#as_json' do
+    let(:project) { create(:project, :repository) }
+    let(:user) { create(:user) }
+    let!(:build) { create(:ci_build, :failed, project: project) }
+    let(:request) { double('request') }
+    let(:entity) { described_class.new(build, request: request, current_user: user, project: project) }
+    subject { entity.as_json }
+
+    before do
+      allow(request).to receive(:current_user).and_return(user)
+
+      project.add_master(user)
+    end
+
+    context 'when the user has access to issues and merge requests' do
+      let!(:merge_request) { create(:merge_request, source_project: project) }
+
+      it 'contains the needed key value pairs' do
+        expect(subject).to include(:coverage, :erased_at, :duration)
+        expect(subject).to include(:artifacts, :runner, :pipeline)
+        expect(subject).to include(:raw_path, :merge_request_path, :new_issue_path)
+      end
+    end
+
+    context 'when the user can only read the build' do
+      it "won't display the paths to issues and merge requests" do
+        expect(subject['new_issue_path']).to be_nil
+        expect(subject['merge_request_path']).to be_nil
+      end
+    end
+  end
+end

spec/serializers/runner_entity_spec.rb

+require 'spec_helper'
+
+describe RunnerEntity do
+  let(:runner) { build(:ci_runner) }
+  let(:entity) { described_class.represent(runner) }
+
+  describe '#as_json' do
+    subject { entity.as_json }
+
+    it 'contains required fields' do
+      expect(subject).to include(:id, :name, :description)
+    end
+  end
+end