Use batching to clear orphans in head_pipeline migration

1 files changed, 39 insertions, 0 deletions

diff --git a/spec/migrations/add_foreign_key_to_merge_requests_spec.rb b/spec/migrations/add_foreign_key_to_merge_requests_spec.rb
new file mode 100644
index 00000000000..d9ad9a585f0
--- /dev/null
+++ b/spec/migrations/add_foreign_key_to_merge_requests_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+require Rails.root.join('db', 'migrate', '20170713104829_add_foreign_key_to_merge_requests.rb')
+
+describe AddForeignKeyToMergeRequests, :migration do
+  let(:projects) { table(:projects) }
+  let(:merge_requests) { table(:merge_requests) }
+  let(:pipelines) { table(:ci_pipelines) }
+
+  before do
+    projects.create!(name: 'gitlab', path: 'gitlab-org/gitlab-ce')
+    pipelines.create!(project_id: projects.first.id,
+                      ref: 'some-branch',
+                      sha: 'abc12345')
+
+    # merge request without a pipeline
+    create_merge_request(head_pipeline_id: nil)
+
+    # merge request with non-existent pipeline
+    create_merge_request(head_pipeline_id: 1234)
+
+    # merge reqeust with existing pipeline assigned
+    create_merge_request(head_pipeline_id: pipelines.first.id)
+  end
+
+  it 'correctly adds a foreign key to head_pipeline_id' do
+    migrate!
+
+    expect(merge_requests.first.head_pipeline_id).to be_nil
+    expect(merge_requests.second.head_pipeline_id).to be_nil
+    expect(merge_requests.third.head_pipeline_id).to eq pipelines.first.id
+  end
+
+  def create_merge_request(**opts)
+    merge_requests.create!(source_project_id: projects.first.id,
+                           target_project_id: projects.first.id,
+                           source_branch: 'some-branch',
+                           target_branch: 'master', **opts)
+  end
+end