2 files changed, 112 insertions, 1 deletions
diff --git a/activerecord/test/cases/migration/helper.rb b/activerecord/test/cases/migration/helper.rb
index 20f26786f0..768ebc5861 100644
--- a/activerecord/test/cases/migration/helper.rb
+++ b/activerecord/test/cases/migration/helper.rb
@@ -14,7 +14,7 @@ module ActiveRecord
     module TestHelper
       attr_reader :connection, :table_name
 
-      CONNECTION_METHODS = %w[add_column remove_column rename_column add_index change_column rename_table]
+      CONNECTION_METHODS = %w[add_column remove_column rename_column add_index change_column rename_table column_exists? index_exists? add_reference add_belongs_to remove_reference remove_references remove_belongs_to]
 
       class TestModel < ActiveRecord::Base
         self.table_name = :test_models
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..144302bd4a
--- /dev/null
+++ b/activerecord/test/cases/migration/references_statements_test.rb
@@ -0,0 +1,111 @@
+require "cases/migration/helper"
+
+module ActiveRecord
+  class Migration
+    class ReferencesStatementsTest < ActiveRecord::TestCase
+      include ActiveRecord::Migration::TestHelper
+
+      self.use_transactional_fixtures = 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
+        refute 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_creates_reference_id_index
+        add_reference table_name, :user, index: true
+        assert index_exists?(table_name, :user_id)
+      end
+
+      def test_does_not_create_reference_id_index
+        add_reference table_name, :user
+        refute 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_id, :taggable_type])
+      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_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_deletes_reference_id_column
+        remove_reference table_name, :supplier
+        refute column_exists?(table_name, :supplier_id, :integer)
+      end
+
+      def test_deletes_reference_id_index
+        remove_reference table_name, :supplier
+        refute index_exists?(table_name, :supplier_id)
+      end
+      
+      def test_does_not_delete_reference_type_column
+        with_polymorphic_column do
+          remove_reference table_name, :supplier
+
+          refute 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
+          refute 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
+          refute 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
+        refute 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