1 files changed, 104 insertions, 0 deletions
diff --git a/spec/rubocop/cop/migration/background_migration_base_class_spec.rb b/spec/rubocop/cop/migration/background_migration_base_class_spec.rb
new file mode 100644
index 00000000000..0a110418139
--- /dev/null
+++ b/spec/rubocop/cop/migration/background_migration_base_class_spec.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require_relative '../../../../rubocop/cop/migration/background_migration_base_class'
+
+RSpec.describe RuboCop::Cop::Migration::BackgroundMigrationBaseClass do
+  subject(:cop) { described_class.new }
+
+  context 'when the migration class inherits from BatchedMigrationJob' do
+    it 'does not register any offenses' do
+      expect_no_offenses(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob < BatchedMigrationJob
+              def perform
+                connection.execute("select 1")
+              end
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when the migration class inherits from the namespaced BatchedMigrationJob' do
+    it 'does not register any offenses' do
+      expect_no_offenses(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob < Gitlab::BackgroundMigration::BatchedMigrationJob
+              def perform
+                connection.execute("select 1")
+              end
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when the migration class inherits from the top-level namespaced BatchedMigrationJob' do
+    it 'does not register any offenses' do
+      expect_no_offenses(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob < ::Gitlab::BackgroundMigration::BatchedMigrationJob
+              def perform
+                connection.execute("select 1")
+              end
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when a nested class is used inside the job class' do
+    it 'does not register any offenses' do
+      expect_no_offenses(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob < BatchedMigrationJob
+              class Project < ApplicationRecord
+                self.table_name = 'projects'
+              end
+
+              def perform
+                Project.update!(name: 'hi')
+              end
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when the migration class inherits from another class' do
+    it 'registers an offense' do
+      expect_offense(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob < SomeOtherClass
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #{described_class::MSG}
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  context 'when the migration class does not inherit from anything' do
+    it 'registers an offense' do
+      expect_offense(<<~RUBY)
+        module Gitlab
+          module BackgroundMigration
+            class MyJob
+            ^^^^^^^^^^^ #{described_class::MSG}
+            end
+          end
+        end
+      RUBY
+    end
+  end
+end