1 files changed, 160 insertions, 0 deletions
diff --git a/spec/lib/gitlab/database/background_migration/batched_migration_spec.rb b/spec/lib/gitlab/database/background_migration/batched_migration_spec.rb
new file mode 100644
index 00000000000..f4a939e7c1f
--- /dev/null
+++ b/spec/lib/gitlab/database/background_migration/batched_migration_spec.rb
@@ -0,0 +1,160 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::BackgroundMigration::BatchedMigration, type: :model do
+  it_behaves_like 'having unique enum values'
+
+  describe 'associations' do
+    it { is_expected.to have_many(:batched_jobs).with_foreign_key(:batched_background_migration_id) }
+
+    describe '#last_job' do
+      let!(:batched_migration) { create(:batched_background_migration) }
+      let!(:batched_job1) { create(:batched_background_migration_job, batched_migration: batched_migration) }
+      let!(:batched_job2) { create(:batched_background_migration_job, batched_migration: batched_migration) }
+
+      it 'returns the most recent (in order of id) batched job' do
+        expect(batched_migration.last_job).to eq(batched_job2)
+      end
+    end
+  end
+
+  describe '.queue_order' do
+    let!(:migration1) { create(:batched_background_migration) }
+    let!(:migration2) { create(:batched_background_migration) }
+    let!(:migration3) { create(:batched_background_migration) }
+
+    it 'returns batched migrations ordered by their id' do
+      expect(described_class.queue_order.all).to eq([migration1, migration2, migration3])
+    end
+  end
+
+  describe '#interval_elapsed?' do
+    context 'when the migration has no last_job' do
+      let(:batched_migration) { build(:batched_background_migration) }
+
+      it 'returns true' do
+        expect(batched_migration.interval_elapsed?).to eq(true)
+      end
+    end
+
+    context 'when the migration has a last_job' do
+      let(:interval) { 2.minutes }
+      let(:batched_migration) { create(:batched_background_migration, interval: interval) }
+
+      context 'when the last_job is less than an interval old' do
+        it 'returns false' do
+          freeze_time do
+            create(:batched_background_migration_job,
+              batched_migration: batched_migration,
+              created_at: Time.current - 1.minute)
+
+            expect(batched_migration.interval_elapsed?).to eq(false)
+          end
+        end
+      end
+
+      context 'when the last_job is exactly an interval old' do
+        it 'returns true' do
+          freeze_time do
+            create(:batched_background_migration_job,
+              batched_migration: batched_migration,
+              created_at: Time.current - 2.minutes)
+
+            expect(batched_migration.interval_elapsed?).to eq(true)
+          end
+        end
+      end
+
+      context 'when the last_job is more than an interval old' do
+        it 'returns true' do
+          freeze_time do
+            create(:batched_background_migration_job,
+              batched_migration: batched_migration,
+              created_at: Time.current - 3.minutes)
+
+            expect(batched_migration.interval_elapsed?).to eq(true)
+          end
+        end
+      end
+    end
+  end
+
+  describe '#create_batched_job!' do
+    let(:batched_migration) { create(:batched_background_migration) }
+
+    it 'creates a batched_job with the correct batch configuration' do
+      batched_job = batched_migration.create_batched_job!(1, 5)
+
+      expect(batched_job).to have_attributes(
+        min_value: 1,
+        max_value: 5,
+        batch_size: batched_migration.batch_size,
+        sub_batch_size: batched_migration.sub_batch_size)
+    end
+  end
+
+  describe '#next_min_value' do
+    let!(:batched_migration) { create(:batched_background_migration) }
+
+    context 'when a previous job exists' do
+      let!(:batched_job) { create(:batched_background_migration_job, batched_migration: batched_migration) }
+
+      it 'returns the next value after the previous maximum' do
+        expect(batched_migration.next_min_value).to eq(batched_job.max_value + 1)
+      end
+    end
+
+    context 'when a previous job does not exist' do
+      it 'returns the migration minimum value' do
+        expect(batched_migration.next_min_value).to eq(batched_migration.min_value)
+      end
+    end
+  end
+
+  describe '#job_class' do
+    let(:job_class) { Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJob }
+    let(:batched_migration) { build(:batched_background_migration) }
+
+    it 'returns the class of the job for the migration' do
+      expect(batched_migration.job_class).to eq(job_class)
+    end
+  end
+
+  describe '#batch_class' do
+    let(:batch_class) { Gitlab::BackgroundMigration::BatchingStrategies::PrimaryKeyBatchingStrategy}
+    let(:batched_migration) { build(:batched_background_migration) }
+
+    it 'returns the class of the batch strategy for the migration' do
+      expect(batched_migration.batch_class).to eq(batch_class)
+    end
+  end
+
+  shared_examples_for 'an attr_writer that demodulizes assigned class names' do |attribute_name|
+    let(:batched_migration) { build(:batched_background_migration) }
+
+    context 'when a module name exists' do
+      it 'removes the module name' do
+        batched_migration.public_send(:"#{attribute_name}=", '::Foo::Bar')
+
+        expect(batched_migration[attribute_name]).to eq('Bar')
+      end
+    end
+
+    context 'when a module name does not exist' do
+      it 'does not change the given class name' do
+        batched_migration.public_send(:"#{attribute_name}=", 'Bar')
+
+        expect(batched_migration[attribute_name]).to eq('Bar')
+      end
+    end
+  end
+
+  describe '#job_class_name=' do
+    it_behaves_like 'an attr_writer that demodulizes assigned class names', :job_class_name
+  end
+
+  describe '#batch_class_name=' do
+    it_behaves_like 'an attr_writer that demodulizes assigned class names', :batch_class_name
+  end
+end