1 files changed, 138 insertions, 0 deletions
diff --git a/activerecord/test/cases/migration/references_statements_test.rb b/activerecord/test/cases/migration/references_statements_test.rb
new file mode 100644
index 0000000000..769241ba12
--- /dev/null
+++ b/activerecord/test/cases/migration/references_statements_test.rb
@@ -0,0 +1,138 @@
+# frozen_string_literal: true
+
+require "cases/migration/helper"
+
+module ActiveRecord
+  class Migration
+    class ReferencesStatementsTest < ActiveRecord::TestCase
+      include ActiveRecord::Migration::TestHelper
+
+      self.use_transactional_tests = false
+
+      def setup
+        super
+        @table_name = :test_models
+
+        add_column table_name, :supplier_id, :integer
+        add_index table_name, :supplier_id
+      end
+
+      def test_creates_reference_id_column
+        add_reference table_name, :user
+        assert column_exists?(table_name, :user_id, :integer)
+      end
+
+      def test_does_not_create_reference_type_column
+        add_reference table_name, :taggable
+        assert_not column_exists?(table_name, :taggable_type, :string)
+      end
+
+      def test_creates_reference_type_column
+        add_reference table_name, :taggable, polymorphic: true
+        assert column_exists?(table_name, :taggable_type, :string)
+      end
+
+      def test_does_not_create_reference_id_index_if_index_is_false
+        add_reference table_name, :user, index: false
+        assert_not index_exists?(table_name, :user_id)
+      end
+
+      def test_create_reference_id_index_even_if_index_option_is_not_passed
+        add_reference table_name, :user
+        assert index_exists?(table_name, :user_id)
+      end
+
+      def test_creates_polymorphic_index
+        add_reference table_name, :taggable, polymorphic: true, index: true
+        assert index_exists?(table_name, [:taggable_type, :taggable_id])
+      end
+
+      def test_creates_reference_type_column_with_default
+        add_reference table_name, :taggable, polymorphic: { default: "Photo" }, index: true
+        assert column_exists?(table_name, :taggable_type, :string, default: "Photo")
+      end
+
+      def test_creates_reference_type_column_with_not_null
+        connection.create_table table_name, force: true do |t|
+          t.references :taggable, null: false, polymorphic: true
+        end
+        assert column_exists?(table_name, :taggable_id, :integer, null: false)
+        assert column_exists?(table_name, :taggable_type, :string, null: false)
+      end
+
+      def test_does_not_share_options_with_reference_type_column
+        add_reference table_name, :taggable, type: :integer, limit: 2, polymorphic: true
+        assert column_exists?(table_name, :taggable_id, :integer, limit: 2)
+        assert column_exists?(table_name, :taggable_type, :string)
+        assert_not column_exists?(table_name, :taggable_type, :string, limit: 2)
+      end
+
+      def test_creates_named_index
+        add_reference table_name, :tag, index: { name: "index_taggings_on_tag_id" }
+        assert index_exists?(table_name, :tag_id, name: "index_taggings_on_tag_id")
+      end
+
+      def test_creates_named_unique_index
+        add_reference table_name, :tag, index: { name: "index_taggings_on_tag_id", unique: true }
+        assert index_exists?(table_name, :tag_id, name: "index_taggings_on_tag_id", unique: true)
+      end
+
+      def test_creates_reference_id_with_specified_type
+        add_reference table_name, :user, type: :string
+        assert column_exists?(table_name, :user_id, :string)
+      end
+
+      def test_deletes_reference_id_column
+        remove_reference table_name, :supplier
+        assert_not column_exists?(table_name, :supplier_id, :integer)
+      end
+
+      def test_deletes_reference_id_index
+        remove_reference table_name, :supplier
+        assert_not index_exists?(table_name, :supplier_id)
+      end
+
+      def test_does_not_delete_reference_type_column
+        with_polymorphic_column do
+          remove_reference table_name, :supplier
+
+          assert_not column_exists?(table_name, :supplier_id, :integer)
+          assert column_exists?(table_name, :supplier_type, :string)
+        end
+      end
+
+      def test_deletes_reference_type_column
+        with_polymorphic_column do
+          remove_reference table_name, :supplier, polymorphic: true
+          assert_not column_exists?(table_name, :supplier_type, :string)
+        end
+      end
+
+      def test_deletes_polymorphic_index
+        with_polymorphic_column do
+          remove_reference table_name, :supplier, polymorphic: true
+          assert_not index_exists?(table_name, [:supplier_id, :supplier_type])
+        end
+      end
+
+      def test_add_belongs_to_alias
+        add_belongs_to table_name, :user
+        assert column_exists?(table_name, :user_id, :integer)
+      end
+
+      def test_remove_belongs_to_alias
+        remove_belongs_to table_name, :supplier
+        assert_not column_exists?(table_name, :supplier_id, :integer)
+      end
+
+      private
+
+        def with_polymorphic_column
+          add_column table_name, :supplier_type, :string
+          add_index table_name, [:supplier_id, :supplier_type]
+
+          yield
+        end
+    end
+  end
+end