Make it possible to inherit global ci config nodes

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

@@ -90,6 +90,8 @@ module Gitlab
               @entries.delete(:type)
             end
+
+            inherit!(deps)
           end
           def name
@@ -102,6 +104,19 @@ module Gitlab
           private
+          def inherit!(deps)
+            return unless deps
+
+            self.class.nodes.each_key do |key|
+              global_entry = deps[key]
+              job_entry = @entries[key]
+
+              if global_entry.specified? && !job_entry.specified?
+                @entries[key] = global_entry
+              end
+            end
+          end
+
           def to_hash
             { name: name,
               before_script: before_script,

spec/lib/gitlab/ci/config/node/global_spec.rb

@@ -14,7 +14,7 @@ describe Gitlab::Ci::Config::Node::Global do
   end
   context 'when hash is valid' do
-    context 'when all entries defined' do
+    context 'when some entries defined' do
       let(:hash) do
         { before_script: ['ls', 'pwd'],
           image: 'ruby:2.2',
@@ -24,7 +24,7 @@ describe Gitlab::Ci::Config::Node::Global do
           stages: ['build', 'pages'],
           cache: { key: 'k', untracked: true, paths: ['public/'] },
           rspec: { script: %w[rspec ls] },
-          spinach: { script: 'spinach' } }
+          spinach: { before_script: [], variables: {}, script: 'spinach' } }
       end
       describe '#compose!' do
@@ -76,6 +76,12 @@ describe Gitlab::Ci::Config::Node::Global do
       context 'when composed' do
         before { global.compose! }
+        describe '#errors' do
+          it 'has no errors' do
+            expect(global.errors).to be_empty
+          end
+        end
+
         describe '#before_script' do
           it 'returns correct script' do
             expect(global.before_script).to eq ['ls', 'pwd']
@@ -135,12 +141,24 @@ describe Gitlab::Ci::Config::Node::Global do
         describe '#jobs' do
           it 'returns jobs configuration' do
             expect(global.jobs).to eq(
-              rspec: { name: :rspec,
-                       script: %w[rspec ls],
-                       stage: 'test' },
+              rspec: { script: %w[rspec ls],
+                       name: :rspec,
+                       before_script: ['ls', 'pwd'],
+                       image: 'ruby:2.2',
+                       services: ['postgres:9.1', 'mysql:5.5'],
+                       stage: 'test',
+                       cache: { key: 'k', untracked: true, paths: ['public/'] },
+                       variables: { VAR: 'value' },
+                       after_script: ['make clean'] },
               spinach: { name: :spinach,
                          script: %w[spinach],
-                         stage: 'test' }
+                         before_script: [],
+                         image: 'ruby:2.2',
+                         services: ['postgres:9.1', 'mysql:5.5'],
+                         stage: 'test',
+                         cache: { key: 'k', untracked: true, paths: ['public/'] },
+                         variables: {},
+                         after_script: ['make clean'] },
             )
           end
         end

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

@@ -3,9 +3,9 @@ require 'spec_helper'
 describe Gitlab::Ci::Config::Node::Job do
   let(:entry) { described_class.new(config, name: :rspec) }
-  before { entry.compose! }
-
   describe 'validations' do
+    before { entry.compose! }
+
     context 'when entry config value is correct' do
       let(:config) { { script: 'rspec' } }
@@ -60,6 +60,8 @@ describe Gitlab::Ci::Config::Node::Job do
   end
   describe '#value' do
+    before { entry.compose! }
+
     context 'when entry is correct' do
       let(:config) do
         { before_script: %w[ls pwd],
@@ -83,4 +85,41 @@ describe Gitlab::Ci::Config::Node::Job do
       expect(entry).to be_relevant
     end
   end
+
+  describe '#compose!' do
+    let(:unspecified) { double('unspecified', 'specified?' => false) }
+
+    let(:specified) do
+      double('specified', 'specified?' => true, value: 'specified')
+    end
+
+    let(:deps) { spy('deps', '[]' => unspecified) }
+
+    context 'when job config overrides global config' do
+      before { entry.compose!(deps) }
+
+      let(:config) do
+        { image: 'some_image', cache: { key: 'test' } }
+      end
+
+      it 'overrides global config' do
+        expect(entry[:image].value).to eq 'some_image'
+        expect(entry[:cache].value).to eq(key: 'test')
+      end
+    end
+
+    context 'when job config does not override global config' do
+      before do
+        allow(deps).to receive('[]').with(:image).and_return(specified)
+        entry.compose!(deps)
+      end
+
+      let(:config) { { script: 'ls', cache: { key: 'test' } } }
+
+      it 'uses config from global entry' do
+        expect(entry[:image].value).to eq 'specified'
+        expect(entry[:cache].value).to eq(key: 'test')
+      end
+    end
+  end
 end