1 files changed, 91 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/copy_column_using_background_migration_job_spec.rb b/spec/lib/gitlab/background_migration/copy_column_using_background_migration_job_spec.rb
new file mode 100644
index 00000000000..110a1ff8a08
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/copy_column_using_background_migration_job_spec.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJob do
+  let(:table_name) { :copy_primary_key_test }
+  let(:test_table) { table(table_name) }
+  let(:sub_batch_size) { 1000 }
+
+  before do
+    ActiveRecord::Base.connection.execute(<<~SQL)
+      CREATE TABLE #{table_name}
+      (
+       id integer NOT NULL,
+       name character varying,
+       fk integer NOT NULL,
+       id_convert_to_bigint bigint DEFAULT 0 NOT NULL,
+       fk_convert_to_bigint bigint DEFAULT 0 NOT NULL,
+       name_convert_to_text text DEFAULT 'no name'
+      );
+    SQL
+
+    # Insert some data, it doesn't make a difference
+    test_table.create!(id: 11, name: 'test1', fk: 1)
+    test_table.create!(id: 12, name: 'test2', fk: 2)
+    test_table.create!(id: 15, name: nil, fk: 3)
+    test_table.create!(id: 19, name: 'test4', fk: 4)
+  end
+
+  after do
+    # Make sure that the temp table we created is dropped (it is not removed by the database_cleaner)
+    ActiveRecord::Base.connection.execute(<<~SQL)
+      DROP TABLE IF EXISTS #{table_name};
+    SQL
+  end
+
+  subject { described_class.new }
+
+  describe '#perform' do
+    let(:migration_class) { described_class.name }
+    let!(:job1) do
+      table(:background_migration_jobs).create!(
+        class_name: migration_class,
+        arguments: [1, 10, table_name, 'id', 'id', 'id_convert_to_bigint', sub_batch_size]
+      )
+    end
+
+    let!(:job2) do
+      table(:background_migration_jobs).create!(
+        class_name: migration_class,
+        arguments: [11, 20, table_name, 'id', 'id', 'id_convert_to_bigint', sub_batch_size]
+      )
+    end
+
+    it 'copies all primary keys in range' do
+      subject.perform(12, 15, table_name, 'id', 'id', 'id_convert_to_bigint', sub_batch_size)
+
+      expect(test_table.where('id = id_convert_to_bigint').pluck(:id)).to contain_exactly(12, 15)
+      expect(test_table.where(id_convert_to_bigint: 0).pluck(:id)).to contain_exactly(11, 19)
+      expect(test_table.all.count).to eq(4)
+    end
+
+    it 'copies all foreign keys in range' do
+      subject.perform(10, 14, table_name, 'id', 'fk', 'fk_convert_to_bigint', sub_batch_size)
+
+      expect(test_table.where('fk = fk_convert_to_bigint').pluck(:id)).to contain_exactly(11, 12)
+      expect(test_table.where(fk_convert_to_bigint: 0).pluck(:id)).to contain_exactly(15, 19)
+      expect(test_table.all.count).to eq(4)
+    end
+
+    it 'copies columns with NULLs' do
+      expect(test_table.where("name_convert_to_text = 'no name'").count).to eq(4)
+
+      subject.perform(10, 20, table_name, 'id', 'name', 'name_convert_to_text', sub_batch_size)
+
+      expect(test_table.where('name = name_convert_to_text').pluck(:id)).to contain_exactly(11, 12, 19)
+      expect(test_table.where('name is NULL and name_convert_to_text is NULL').pluck(:id)).to contain_exactly(15)
+      expect(test_table.where("name_convert_to_text = 'no name'").count).to eq(0)
+    end
+
+    it 'tracks completion with BackgroundMigrationJob' do
+      expect do
+        subject.perform(11, 20, table_name, 'id', 'id', 'id_convert_to_bigint', sub_batch_size)
+      end.to change { Gitlab::Database::BackgroundMigrationJob.succeeded.count }.from(0).to(1)
+
+      expect(job1.reload.status).to eq(0)
+      expect(job2.reload.status).to eq(1)
+      expect(test_table.where('id = id_convert_to_bigint').count).to eq(4)
+    end
+  end
+end