[Django 4.2]fix: swagger_auto_schema applied twice to method

[irtazaakram]

Description

Fixes - AssertionError: swagger_auto_schema applied twice to method

__ ProgramListPaginationViewTests.test_404_with_invalid_pagination_arguments ___

self = <registrar.apps.api.v3.tests.test_views.ProgramListPaginationViewTests testMethod=test_404_with_invalid_pagination_arguments>

    def test_404_with_invalid_pagination_arguments(self):
        with self.assert_tracking(user=self.edx_admin, status_code=404):
>           response = self.get('programs?page_size=100&page=2', self.edx_admin)

registrar/apps/api/v3/tests/test_views.py:85: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
registrar/apps/api/tests/mixins.py:166: in get
    return self.request('get', path, user)
registrar/apps/api/tests/mixins.py:218: in request
    return getattr(self.client, method.lower())(path, **kwargs)
.tox/django42/lib/python3.8/site-packages/rest_framework/test.py:289: in get
    response = super().get(path, data=data, **extra)
.tox/django42/lib/python3.8/site-packages/rest_framework/test.py:206: in get
    return self.generic('GET', path, **r)
.tox/django42/lib/python3.8/site-packages/rest_framework/test.py:234: in generic
    return super().generic(
.tox/django42/lib/python3.8/site-packages/django/test/client.py:609: in generic
    return self.request(**r)
.tox/django42/lib/python3.8/site-packages/rest_framework/test.py:286: in request
    return super().request(**kwargs)
.tox/django42/lib/python3.8/site-packages/rest_framework/test.py:238: in request
    request = super().request(**kwargs)
.tox/django42/lib/python3.8/site-packages/django/test/client.py:891: in request
    self.check_exception(response)
.tox/django42/lib/python3.8/site-packages/django/test/client.py:738: in check_exception
    raise exc_value
.tox/django42/lib/python3.8/site-packages/django/core/handlers/exception.py:55: in inner
    response = get_response(request)
.tox/django42/lib/python3.8/site-packages/django/core/handlers/base.py:197: in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
.tox/django42/lib/python3.8/site-packages/django/views/decorators/csrf.py:56: in wrapper_view
    return view_func(*args, **kwargs)
.tox/django42/lib/python3.8/site-packages/django/views/generic/base.py:104: in view
    return self.dispatch(request, *args, **kwargs)
registrar/apps/api/mixins.py:89: in dispatch
    response = super().dispatch(*args, **kwargs)
.tox/django42/lib/python3.8/site-packages/rest_framework/views.py:509: in dispatch
    response = self.handle_exception(exc)
.tox/django42/lib/python3.8/site-packages/rest_framework/views.py:469: in handle_exception
    self.raise_uncaught_exception(exc)
.tox/django42/lib/python3.8/site-packages/rest_framework/views.py:480: in raise_uncaught_exception
    raise exc
.tox/django42/lib/python3.8/site-packages/rest_framework/views.py:506: in dispatch
    response = handler(request, *args, **kwargs)
.tox/django42/lib/python3.8/site-packages/django/utils/decorators.py:45: in _wrapper
    bound_method = dec(bound_method)
.tox/django42/lib/python3.8/site-packages/edx_api_doc_tools/view_utils.py:143: in schema_inner
    return swagger_auto_schema(
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

view_method = functools.partial(<bound method ListAPIView.get of <registrar.apps.api.v3.views.ProgramListPaginationView object at 0x7f67160707f0>>)

    def decorator(view_method):
        assert not any(hm in extra_overrides for hm in APIView.http_method_names), "HTTP method names not allowed here"
        data = {
            'request_body': request_body,
            'query_serializer': query_serializer,
            'manual_parameters': manual_parameters,
            'operation_id': operation_id,
            'operation_summary': operation_summary,
            'deprecated': deprecated,
            'operation_description': operation_description,
            'security': security,
            'responses': responses,
            'filter_inspectors': list(filter_inspectors) if filter_inspectors else None,
            'paginator_inspectors': list(paginator_inspectors) if paginator_inspectors else None,
            'field_inspectors': list(field_inspectors) if field_inspectors else None,
            'tags': list(tags) if tags else None,
        }
        data = filter_none(data)
        if auto_schema is not unset:
            data['auto_schema'] = auto_schema
        data.update(extra_overrides)
        if not data:  # pragma: no cover
            # no overrides to set, no use in doing more work
            return view_method
    
        # if the method is an @action, it will have a bind_to_methods attribute, or a mapping attribute for drf>3.8
        bind_to_methods = getattr(view_method, 'bind_to_methods', [])
        mapping = getattr(view_method, 'mapping', {})
        mapping_methods = [mth for mth, name in mapping.items() if name == view_method.__name__]
        action_http_methods = bind_to_methods + mapping_methods
    
        # if the method is actually a function based view (@api_view), it will have a 'cls' attribute
        view_cls = getattr(view_method, 'cls', None)
        api_view_http_methods = [m for m in getattr(view_cls, 'http_method_names', []) if hasattr(view_cls, m)]
    
        available_http_methods = api_view_http_methods + action_http_methods
        existing_data = getattr(view_method, '_swagger_auto_schema', {})
    
        _methods = methods
        if methods or method:
            assert available_http_methods, "`method` or `methods` can only be specified on @action or @api_view views"
            assert bool(methods) != bool(method), "specify either method or methods"
            assert not isinstance(methods, str), "`methods` expects to receive a list of methods;" \
                                                 " use `method` for a single argument"
            if method:
                _methods = [method.lower()]
            else:
                _methods = [mth.lower() for mth in methods]
            assert all(mth in available_http_methods for mth in _methods), "http method not bound to view"
            assert not any(mth in existing_data for mth in _methods), "http method defined multiple times"
    
        if available_http_methods:
            # action or api_view
            assert bool(api_view_http_methods) != bool(action_http_methods), "this should never happen"
    
            if len(available_http_methods) > 1:
                assert _methods, \
                    "on multi-method api_view or action, you must specify " \
                    "swagger_auto_schema on a per-method basis using one of the `method` or `methods` arguments"
            else:
                # for a single-method view we assume that single method as the decorator target
                _methods = _methods or available_http_methods
    
            assert not any(hasattr(getattr(view_cls, mth, None), '_swagger_auto_schema') for mth in _methods), \
                "swagger_auto_schema applied twice to method"
            assert not any(mth in existing_data for mth in _methods), "swagger_auto_schema applied twice to method"
            existing_data.update((mth.lower(), data) for mth in _methods)
            view_method._swagger_auto_schema = existing_data
        else:
            assert not _methods, \
                "the methods argument should only be specified when decorating an action; " \
                "you should also ensure that you put the swagger_auto_schema decorator " \
                "AFTER (above) the _route decorator"
>           assert not existing_data, "swagger_auto_schema applied twice to method"
E           AssertionError: swagger_auto_schema applied twice to method

ProgramListPaginationView already inherits same schema from ProgramListView

[schenedx]

Approve. Did you check on local machine that the swagger doc generated have explanations about paginations?

[irtazaakram]

Hi @schenedx,

I've very little info on how to see exaplanations about paginations. This is the view for /api-docs I am getting for v3 locally.

I don't know how to test the API. If there's any testing instructions please share.

Thanks,

[schenedx]

@irtazaakram Looks good. Feel free to merge.