Merge pull request rails#54725 from a5-stable/implement-respond-to-missing-for-migration

Add respond_to_missing? to complement method_missing in ActiveRecord::Migration

Author: byroot

activerecord/lib/active_record/migration.rb

@@ -782,6 +782,11 @@ def load_schema!
             system("bin/rails db:test:prepare")
           end
         end
+
+        def respond_to_missing?(method, include_private = false)
+          return false if nearest_delegate == delegate
+          nearest_delegate.respond_to?(method, include_private)
+        end
     end
 
     def disable_ddl_transaction # :nodoc:
@@ -1170,6 +1175,10 @@ def internal_option?(option_name)
       def command_recorder
         CommandRecorder.new(connection)
       end
+
+      def respond_to_missing?(method, include_private = false)
+        execution_strategy.respond_to?(method, include_private) || super
+      end
   end
 
   # MigrationProxy is used to defer loading of the actual migration classes

activerecord/test/cases/migration_test.rb

@@ -461,6 +461,21 @@ def create_table; "hi mom!"; end
     assert_equal "hi mom!", migration.method_missing(:create_table)
   end
 
+  def test_respond_to_for_migration_method
+    migration_class = Class.new(ActiveRecord::Migration::Current) {
+      def connection
+        Class.new {
+          def create_table; end
+        }.new
+      end
+    }
+
+    migration_class.class_eval { undef_method :create_table }
+    # create_table is handled by method_missing, so respond_to? returns true.
+    assert migration_class.new.respond_to?(:create_table)
+    assert migration_class.respond_to?(:create_table)
+  end
+
   def test_add_table_with_decimals
     Person.lease_connection.drop_table :big_numbers rescue nil