Add specs for builder chain that persist a pipeline

spec/lib/gitlab/ci/pipeline/chain/create_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Ci::Pipeline::Chain::Create do
+  set(:project) { create(:project) }
+  set(:user) { create(:user) }
+
+  let(:pipeline) do
+    build(:ci_pipeline_with_one_job, project: project,
+                                     ref: 'master')
+  end
+
+  let(:command) do
+    double('command', project: project,
+                      current_user: user,
+                      seeds_block: nil)
+  end
+
+  let(:step) { described_class.new(pipeline, command) }
+
+  before do
+    step.perform!
+  end
+
+  context 'when pipeline is ready to be saved' do
+    it 'saves a pipeline' do
+      expect(pipeline).to be_persisted
+    end
+
+    it 'does not break the chain' do
+      expect(step.break?).to be false
+    end
+
+    it 'creates stages' do
+      expect(pipeline.reload.stages).to be_one
+    end
+  end
+
+  context 'when pipeline has validation errors' do
+    let(:pipeline) do
+      build(:ci_pipeline, project: project, ref: nil)
+    end
+
+    it 'breaks the chain' do
+      expect(step.break?).to be true
+    end
+
+    it 'appends validation error' do
+      expect(pipeline.errors.to_a)
+        .to include /Failed to persist the pipeline/
+    end
+  end
+
+  context 'when there is a seed block present' do
+    let(:seeds) { spy('pipeline seeds') }
+
+    let(:command) do
+      double('command', project: project,
+                        current_user: user,
+                        seeds_block: seeds)
+    end
+
+    it 'executes the block' do
+      expect(seeds).to have_received(:call).with(pipeline)
+    end
+  end
+end