Add parallel keyword to CI config

lib/gitlab/ci/config/entry/job.rb

@@ -12,7 +12,7 @@ module Gitlab
           ALLOWED_KEYS = %i[tags script only except type image services
                             allow_failure type stage when start_in artifacts cache
                             dependencies before_script after_script variables
-                            environment coverage retry extends].freeze
+                            environment coverage retry parallel extends].freeze
 
           validations do
             validates :config, allowed_keys: ALLOWED_KEYS
@@ -27,6 +27,8 @@ module Gitlab
               validates :retry, numericality: { only_integer: true,
                                                 greater_than_or_equal_to: 0,
                                                 less_than_or_equal_to: 2 }
+              validates :parallel, numericality: { only_integer: true,
+                                                   greater_than_or_equal_to: 1 }
               validates :when,
                 inclusion: { in: %w[on_success on_failure always manual delayed],
                              message: 'should be on_success, on_failure, ' \
@@ -84,10 +86,11 @@ module Gitlab
 
           helpers :before_script, :script, :stage, :type, :after_script,
                   :cache, :image, :services, :only, :except, :variables,
-                  :artifacts, :commands, :environment, :coverage, :retry
+                  :artifacts, :commands, :environment, :coverage, :retry,
+                  :parallel
 
           attributes :script, :tags, :allow_failure, :when, :dependencies,
-                     :retry, :extends, :start_in
+                     :retry, :parallel, :extends, :start_in
 
           def compose!(deps = nil)
             super do
@@ -156,6 +159,7 @@ module Gitlab
               environment_name: environment_defined? ? environment_value[:name] : nil,
               coverage: coverage_defined? ? coverage_value : nil,
               retry: retry_defined? ? retry_value.to_i : nil,
+              parallel: parallel_defined? ? parallel_value.to_i : nil,
               artifacts: artifacts_value,
               after_script: after_script_value,
               ignore: ignored? }

spec/lib/gitlab/ci/config/entry/job_spec.rb

-require 'fast_spec_helper'
-require_dependency 'active_model'
+require 'spec_helper'
 
 describe Gitlab::Ci::Config::Entry::Job do
   let(:entry) { described_class.new(config, name: :rspec) }
@@ -138,6 +137,36 @@ describe Gitlab::Ci::Config::Entry::Job do
         end
       end
 
+      context 'when parallel value is not correct' do
+        context 'when it is not a numeric value' do
+          let(:config) { { parallel: true } }
+
+          it 'returns error about invalid type' do
+            expect(entry).not_to be_valid
+            expect(entry.errors).to include 'job parallel is not a number'
+          end
+        end
+
+        context 'when it is lower than one' do
+          let(:config) { { parallel: 0 } }
+
+          it 'returns error about value too low' do
+            expect(entry).not_to be_valid
+            expect(entry.errors)
+              .to include 'job parallel must be greater than or equal to 1'
+          end
+        end
+
+        context 'when it is not an integer' do
+          let(:config) { { parallel: 1.5 } }
+
+          it 'returns error about wrong value' do
+            expect(entry).not_to be_valid
+            expect(entry.errors).to include 'job parallel must be an integer'
+          end
+        end
+      end
+
       context 'when delayed job' do
         context 'when start_in is specified' do
           let(:config) { { script: 'echo', when: 'delayed', start_in: '1 day' } }