Add specs for stage status background migration class

spec/lib/gitlab/background_migration/migrate_stage_status_spec.rb

+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::MigrateStageStatus, :migration, schema: 20170711145320 do
+  let(:projects) { table(:projects) }
+  let(:pipelines) { table(:ci_pipelines) }
+  let(:stages) { table(:ci_stages) }
+  let(:jobs) { table(:ci_builds) }
+
+  STATUSES = { created: 0, pending: 1, running: 2, success: 3,
+               failed: 4, canceled: 5, skipped: 6, manual: 7 }.freeze
+
+  before do
+    projects.create!(id: 1, name: 'gitlab1', path: 'gitlab1')
+    pipelines.create!(id: 1, project_id: 1, ref: 'master', sha: 'adf43c3a')
+    stages.create!(id: 1, pipeline_id: 1, project_id: 1, name: 'test', status: nil)
+    stages.create!(id: 2, pipeline_id: 1, project_id: 1, name: 'deploy', status: nil)
+  end
+
+  context 'when stage status is known' do
+    before do
+      create_job(project: 1, pipeline: 1, stage: 'test', status: 'success')
+      create_job(project: 1, pipeline: 1, stage: 'test', status: 'running')
+      create_job(project: 1, pipeline: 1, stage: 'deploy', status: 'failed')
+    end
+
+    it 'sets a correct stage status' do
+      described_class.new.perform(1, 2)
+
+      expect(stages.first.status).to eq STATUSES[:running]
+      expect(stages.second.status).to eq STATUSES[:failed]
+    end
+  end
+
+  context 'when stage status is not known' do
+    it 'sets a skipped stage status' do
+      described_class.new.perform(1, 2)
+
+      expect(stages.first.status).to eq STATUSES[:skipped]
+      expect(stages.second.status).to eq STATUSES[:skipped]
+    end
+  end
+
+  context 'when stage status includes status of a retried job' do
+    before do
+      create_job(project: 1, pipeline: 1, stage: 'test', status: 'canceled')
+      create_job(project: 1, pipeline: 1, stage: 'deploy', status: 'failed', retried: true)
+      create_job(project: 1, pipeline: 1, stage: 'deploy', status: 'success')
+    end
+
+    it 'sets a correct stage status' do
+      described_class.new.perform(1, 2)
+
+      expect(stages.first.status).to eq STATUSES[:canceled]
+      expect(stages.second.status).to eq STATUSES[:success]
+    end
+  end
+
+  context 'when some job in the stage is blocked / manual' do
+    before do
+      create_job(project: 1, pipeline: 1, stage: 'test', status: 'failed')
+      create_job(project: 1, pipeline: 1, stage: 'test', status: 'manual')
+      create_job(project: 1, pipeline: 1, stage: 'deploy', status: 'success', when: 'manual')
+    end
+
+    it 'sets a correct stage status' do
+      described_class.new.perform(1, 2)
+
+      expect(stages.first.status).to eq STATUSES[:manual]
+      expect(stages.second.status).to eq STATUSES[:success]
+    end
+  end
+
+  def create_job(project:, pipeline:, stage:, status:, **opts)
+    stages = { test: 1, build: 2, deploy: 3 }
+
+    jobs.create!(project_id: project, commit_id: pipeline,
+                 stage_idx: stages[stage.to_sym], stage: stage,
+                 status: status, **opts)
+  end
+end