Merge branch 'fix/ci-config-hidden-key-validation' into 'master'

Do not enforce using a hash with hidden ci key

## What does this MR do?

This MR remove the validation rule that was to strict.

## Why was this MR needed?

Enforcing hidden CI job configuration to be a hash, narrows options of using YAML anchors, and was not backwards compatbile.

## 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)
- Tests
  - [x] Added for this feature/bug
  - [ ] 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 #21512

See merge request !6079

2 files changed, 4 insertions, 15 deletions

diff --git a/spec/lib/gitlab/ci/config/node/hidden_job_spec.rb b/spec/lib/gitlab/ci/config/node/hidden_spec.rb
index cc44e2cc054..61e2a554419 100644
--- a/spec/lib/gitlab/ci/config/node/hidden_job_spec.rb
+++ b/spec/lib/gitlab/ci/config/node/hidden_spec.rb
@@ -1,15 +1,15 @@
 require 'spec_helper'
 
-describe Gitlab::Ci::Config::Node::HiddenJob do
+describe Gitlab::Ci::Config::Node::Hidden do
   let(:entry) { described_class.new(config) }
 
   describe 'validations' do
     context 'when entry config value is correct' do
-      let(:config) { { image: 'ruby:2.2' } }
+      let(:config) { [:some, :array] }
 
       describe '#value' do
         it 'returns key value' do
-          expect(entry.value).to eq(image: 'ruby:2.2')
+          expect(entry.value).to eq [:some, :array]
         end
       end
 
@@ -21,17 +21,6 @@ describe Gitlab::Ci::Config::Node::HiddenJob do
     end
 
     context 'when entry value is not correct' do
-      context 'incorrect config value type' do
-        let(:config) { ['incorrect'] }
-
-        describe '#errors' do
-          it 'saves errors' do
-            expect(entry.errors)
-              .to include 'hidden job config should be a hash'
-          end
-        end
-      end
-
       context 'when config is empty' do
         let(:config) { {} }
 
diff --git a/spec/lib/gitlab/ci/config/node/jobs_spec.rb b/spec/lib/gitlab/ci/config/node/jobs_spec.rb
index b8d9c70479c..ae2c88aac37 100644
--- a/spec/lib/gitlab/ci/config/node/jobs_spec.rb
+++ b/spec/lib/gitlab/ci/config/node/jobs_spec.rb
@@ -74,7 +74,7 @@ describe Gitlab::Ci::Config::Node::Jobs do
         expect(entry.descendants.first(2))
           .to all(be_an_instance_of(Gitlab::Ci::Config::Node::Job))
         expect(entry.descendants.last)
-          .to be_an_instance_of(Gitlab::Ci::Config::Node::HiddenJob)
+          .to be_an_instance_of(Gitlab::Ci::Config::Node::Hidden)
       end
     end