Component schema property ordering regression in ApiSpec.to_yaml() method

[vorticity]

In apispec-5.1.1 schema property ordering in the yaml output matched the order of fields in the marshmallow schema, so long as you added a Meta() class to the schema, with an ordered=True attribute. As of apispec-5.2.0 the marshmallow schema field ordering is no longer respected - instead the schema property ordering is always alphabetical.

My workaround is to re-implement YamlDumper and _represent_dict() functionality that was in yaml_utils up to apispec-5.1.1 with an additional add_representer() call to ensure OrderedDict and dict instances are both ordered correctly and use this instead of the to_yaml() method:

def ordered_yaml_dump(data, stream=None, Dumper=SafeDumper, **kwds):
    class OrderedDumper(Dumper):
        pass

    def _represent_dict(dumper, data):
        return dumper.represent_mapping(yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG, data.items())

    OrderedDumper.add_representer(OrderedDict, _dict_representer)
    OrderedDumper.add_representer(dict, _dict_representer)
    return yaml.dump(data, stream, OrderedDumper, **kwds)

Related commit: 09dd98f

[vorticity]

Some more testing reveals that the schema property ordering is respected and matches the output from the OrderedDumper if you set sort_keys=False in yaml_dump_kwargs ie:

spec.to_yaml(yaml_dump_kwargs={"sort_keys": False})

In either case, the output of ApiSpec.to_yaml() in the current version differs from the output of the same method in apispec-5.1.1

[lafrech]

Thanks for reporting and investigating.

What about this?

def dict_to_yaml(dic, yaml_dump_kwargs=None):
    # By default, don't order alphabetically to respect schema order
    yaml_dump_kwargs.setdefault("sort_keys", False)
    if yaml_dump_kwargs is None:
        yaml_dump_kwargs = {}
    return yaml.dump(dic, **yaml_dump_kwargs)

Would you like to send a PR?

[vorticity]

Thanks for the quick response, here is the PR: #769

[lafrech]

Closed by #769.

And released.

Thanks.