1 files changed, 81 insertions, 0 deletions
diff --git a/spec/rubocop/cop/migration/versioned_migration_class_spec.rb b/spec/rubocop/cop/migration/versioned_migration_class_spec.rb
new file mode 100644
index 00000000000..d9b0cd4546c
--- /dev/null
+++ b/spec/rubocop/cop/migration/versioned_migration_class_spec.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require_relative '../../../../rubocop/cop/migration/versioned_migration_class'
+
+RSpec.describe RuboCop::Cop::Migration::VersionedMigrationClass do
+  subject(:cop) { described_class.new }
+
+  let(:migration) do
+    <<~SOURCE
+      class TestMigration < Gitlab::Database::Migration[1.0]
+        def up
+          execute 'select 1'
+        end
+
+        def down
+          execute 'select 1'
+        end
+      end
+    SOURCE
+  end
+
+  shared_examples 'a disabled cop' do
+    it 'does not register any offenses' do
+      expect_no_offenses(migration)
+    end
+  end
+
+  context 'outside of a migration' do
+    it_behaves_like 'a disabled cop'
+  end
+
+  context 'in migration' do
+    before do
+      allow(cop).to receive(:in_migration?).and_return(true)
+    end
+
+    context 'in an old migration' do
+      before do
+        allow(cop).to receive(:version).and_return(described_class::ENFORCED_SINCE - 5)
+      end
+
+      it_behaves_like 'a disabled cop'
+    end
+
+    context 'that is recent' do
+      before do
+        allow(cop).to receive(:version).and_return(described_class::ENFORCED_SINCE + 5)
+      end
+
+      it 'adds an offence if inheriting from ActiveRecord::Migration' do
+        expect_offense(<<~RUBY)
+          class MyMigration < ActiveRecord::Migration[6.1]
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Don't inherit from ActiveRecord::Migration but use Gitlab::Database::Migration[1.0] instead. See https://docs.gitlab.com/ee/development/migration_style_guide.html#migration-helpers-and-versioning.
+          end
+        RUBY
+      end
+
+      it 'adds an offence if including Gitlab::Database::MigrationHelpers directly' do
+        expect_offense(<<~RUBY)
+          class MyMigration < Gitlab::Database::Migration[1.0]
+            include Gitlab::Database::MigrationHelpers
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Don't include migration helper modules directly. Inherit from Gitlab::Database::Migration[1.0] instead. See https://docs.gitlab.com/ee/development/migration_style_guide.html#migration-helpers-and-versioning.
+          end
+        RUBY
+      end
+
+      it 'excludes ActiveRecord classes defined inside the migration' do
+        expect_no_offenses(<<~RUBY)
+          class TestMigration < Gitlab::Database::Migration[1.0]
+            class TestModel < ApplicationRecord
+            end
+
+            class AnotherTestModel < ActiveRecord::Base
+            end
+          end
+        RUBY
+      end
+    end
+  end
+end