Add references statements to migration generator

AddXXXToYYY/RemoveXXXFromYYY migrations are produced with references
statements, for instance

    rails g migration AddReferencesToProducts user:references
supplier:references{polymorphic}

will generate the migration with:

    add_reference :products, :user, index: true
    add_reference :products, :supplier, polymorphic: true, index: true

1 files changed, 29 insertions, 0 deletions

diff --git a/railties/test/generators/migration_generator_test.rb b/railties/test/generators/migration_generator_test.rb
index b320e40654..86e3793289 100644
--- a/railties/test/generators/migration_generator_test.rb
+++ b/railties/test/generators/migration_generator_test.rb
@@ -76,6 +76,23 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_remove_migration_with_references_options
+    migration = "remove_references_from_books"
+    run_generator [migration, "author:belongs_to", "distributor:references{polymorphic}"]
+
+    assert_migration "db/migrate/#{migration}.rb" do |content|
+      assert_method :up, content do |up|
+        assert_match(/remove_reference :books, :author/, up)
+        assert_match(/remove_reference :books, :distributor, polymorphic: true/, up)
+      end
+
+      assert_method :down, content do |down|
+        assert_match(/add_reference :books, :author, index: true/, down)
+        assert_match(/add_reference :books, :distributor, polymorphic: true, index: true/, down)
+      end
+    end
+  end
+
   def test_add_migration_with_attributes_and_indices
     migration = "add_title_with_index_and_body_to_posts"
     run_generator [migration, "title:string:index", "body:text", "user_id:integer:uniq"]
@@ -138,6 +155,18 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_add_migration_with_references_options
+    migration = "add_references_to_books"
+    run_generator [migration, "author:belongs_to", "distributor:references{polymorphic}"]
+
+    assert_migration "db/migrate/#{migration}.rb" do |content|
+      assert_method :change, content do |up|
+        assert_match(/add_reference :books, :author, index: true/, up)
+        assert_match(/add_reference :books, :distributor, polymorphic: true, index: true/, up)
+      end
+    end
+  end
+
   def test_should_create_empty_migrations_if_name_not_start_with_add_or_remove
     migration = "create_books"
     run_generator [migration, "title:string", "content:text"]