Allow fixtures YAML files to set the model class in the file itself

Currently, `set_fixture_class` is only available using the
`TestFixtures` concern and it is ignored for `rake db:fixtures:load`.
Using the correct model class, it is possible for the fixture load
to also load the associations from the YAML files (e.g., `:belongs_to`
and `:has_many`).

1 files changed, 10 insertions, 0 deletions

diff --git a/activerecord/test/cases/fixture_set/file_test.rb b/activerecord/test/cases/fixture_set/file_test.rb
index 92efa8aca7..79951c91c9 100644
--- a/activerecord/test/cases/fixture_set/file_test.rb
+++ b/activerecord/test/cases/fixture_set/file_test.rb
@@ -123,6 +123,16 @@ END
         end
       end
 
+      def test_fixture_model_class_and_rows
+        File.open(::File.join(FIXTURES_ROOT, 'other_posts.yml')) do |fh|
+          assert_equal 'Post', fh.model_class
+
+          fixture_names = []
+          fh.each { |fixture_name, _| fixture_names << fixture_name }
+          assert_equal ['second_welcome'], fixture_names
+        end
+      end
+
       private
       def tmp_yaml(name, contents)
         t = Tempfile.new name