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

11 files changed, 170 insertions, 21 deletions

diff --git a/app/controllers/projects/jobs_controller.rb b/app/controllers/projects/jobs_controller.rb
index d2cd1cfdab8..9b8a9eedfef 100644
--- a/app/controllers/projects/jobs_controller.rb
+++ b/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
diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index 60b71ff0d93..ff6860bc181 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -204,14 +204,17 @@ module Ci
     end
 
     def merge_request
-      merge_requests = MergeRequest.includes(:merge_request_diff)
-                                   .where(source_branch: ref,
-                                          source_project: pipeline.project)
-                                   .reorder(iid: :asc)
-
-      merge_requests.find do |merge_request|
-        merge_request.commits_sha.include?(pipeline.sha)
-      end
+      @merge_request ||=
+        begin
+          merge_requests = MergeRequest.includes(:merge_request_diff)
+            .where(source_branch: ref,
+                   source_project: pipeline.project)
+            .reorder(iid: :asc)
+
+          merge_requests.find do |merge_request|
+            merge_request.commits_sha.include?(pipeline.sha)
+          end
+        end
     end
 
     def repo_url
diff --git a/app/serializers/build_details_entity.rb b/app/serializers/build_details_entity.rb
new file mode 100644
index 00000000000..08c5e69180c
--- /dev/null
+++ b/app/serializers/build_details_entity.rb
@@ -0,0 +1,34 @@
+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
diff --git a/app/serializers/build_serializer.rb b/app/serializers/build_serializer.rb
index 79b67001199..7b501a52604 100644
--- a/app/serializers/build_serializer.rb
+++ b/app/serializers/build_serializer.rb
@@ -1,8 +1,10 @@
 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
diff --git a/app/serializers/runner_entity.rb b/app/serializers/runner_entity.rb
new file mode 100644
index 00000000000..77d6de6e84c
--- /dev/null
+++ b/app/serializers/runner_entity.rb
@@ -0,0 +1,3 @@
+class RunnerEntity < Grape::Entity
+  expose :id, :name, :description
+end
diff --git a/changelogs/unreleased/zj-job-view-goes-real-time.yml b/changelogs/unreleased/zj-job-view-goes-real-time.yml
new file mode 100644
index 00000000000..376c9dfa65f
--- /dev/null
+++ b/changelogs/unreleased/zj-job-view-goes-real-time.yml
@@ -0,0 +1,4 @@
+---
+title: Job details page update real time
+merge_request: 11651
+author:
diff --git a/lib/gitlab/etag_caching/router.rb b/lib/gitlab/etag_caching/router.rb
index d137cc1bae6..53f3f442bc3 100644
--- a/lib/gitlab/etag_caching/router.rb
+++ b/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
 
diff --git a/spec/controllers/projects/jobs_controller_spec.rb b/spec/controllers/projects/jobs_controller_spec.rb
index 838bdae1445..7109310b6df 100644
--- a/spec/controllers/projects/jobs_controller_spec.rb
+++ b/spec/controllers/projects/jobs_controller_spec.rb
@@ -101,26 +101,48 @@ 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) }
 
-      before do
-        get_show(id: build.id)
+    context 'when requesting HTML' do
+      context 'when build exists' do
+        before do
+          get_show(id: build.id)
+        end
+
+        it 'has a build' do
+          expect(response).to have_http_status(:ok)
+          expect(assigns(:build).id).to eq(build.id)
+        end
       end
 
-      it 'has a build' do
-        expect(response).to have_http_status(:ok)
-        expect(assigns(:build).id).to eq(build.id)
+      context 'when build does not exist' do
+        before do
+          get_show(id: 1234)
+        end
+
+        it 'renders not_found' do
+          expect(response).to have_http_status(:not_found)
+        end
       end
     end
 
-    context 'when build does not exist' do
+    context 'when requesting JSON' do
+      let(:merge_request) { create(:merge_request, source_project: project) }
+
       before do
-        get_show(id: 1234)
+        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 'renders not_found' do
-        expect(response).to have_http_status(:not_found)
+      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
 
diff --git a/spec/lib/gitlab/etag_caching/router_spec.rb b/spec/lib/gitlab/etag_caching/router_spec.rb
index 46a238b17f4..22494f4dcf5 100644
--- a/spec/lib/gitlab/etag_caching/router_spec.rb
+++ b/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'
diff --git a/spec/serializers/build_details_entity_spec.rb b/spec/serializers/build_details_entity_spec.rb
new file mode 100644
index 00000000000..4b827a0994c
--- /dev/null
+++ b/spec/serializers/build_details_entity_spec.rb
@@ -0,0 +1,39 @@
+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
diff --git a/spec/serializers/runner_entity_spec.rb b/spec/serializers/runner_entity_spec.rb
new file mode 100644
index 00000000000..eb662a10b7e
--- /dev/null
+++ b/spec/serializers/runner_entity_spec.rb
@@ -0,0 +1,14 @@
+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