1 files changed, 50 insertions, 0 deletions
diff --git a/spec/rubocop/cop/migration/prevent_index_creation_spec.rb b/spec/rubocop/cop/migration/prevent_index_creation_spec.rb
new file mode 100644
index 00000000000..a3965f54bbd
--- /dev/null
+++ b/spec/rubocop/cop/migration/prevent_index_creation_spec.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require_relative '../../../../rubocop/cop/migration/prevent_index_creation'
+
+RSpec.describe RuboCop::Cop::Migration::PreventIndexCreation do
+  subject(:cop) { described_class.new }
+
+  context 'when in migration' do
+    before do
+      allow(cop).to receive(:in_migration?).and_return(true)
+    end
+
+    context 'when adding an index to a forbidden table' do
+      it 'registers an offense when add_index is used' do
+        expect_offense(<<~RUBY)
+          def change
+            add_index :ci_builds, :protected
+            ^^^^^^^^^ Adding new index to ci_builds is forbidden, see https://gitlab.com/gitlab-org/gitlab/-/issues/332886
+          end
+        RUBY
+      end
+
+      it 'registers an offense when add_concurrent_index is used' do
+        expect_offense(<<~RUBY)
+          def change
+            add_concurrent_index :ci_builds, :protected
+            ^^^^^^^^^^^^^^^^^^^^ Adding new index to ci_builds is forbidden, see https://gitlab.com/gitlab-org/gitlab/-/issues/332886
+          end
+        RUBY
+      end
+    end
+
+    context 'when adding an index to a regular table' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          def change
+            add_index :ci_pipelines, :locked
+          end
+        RUBY
+      end
+    end
+  end
+
+  context 'when outside of migration' do
+    it 'does not register an offense' do
+      expect_no_offenses('def change; add_index :table, :column; end')
+    end
+  end
+end