diff options
| -rw-r--r-- | rest_framework/utils/model_meta.py | 6 | ||||
| -rw-r--r-- | tests/test_utils.py | 33 |
2 files changed, 38 insertions, 1 deletions
diff --git a/rest_framework/utils/model_meta.py b/rest_framework/utils/model_meta.py index 82361edf..54f9310d 100644 --- a/rest_framework/utils/model_meta.py +++ b/rest_framework/utils/model_meta.py @@ -43,7 +43,11 @@ def _resolve_model(obj): """ if isinstance(obj, six.string_types) and len(obj.split('.')) == 2: app_name, model_name = obj.split('.') - return models.get_model(app_name, model_name) + resolved_model = models.get_model(app_name, model_name) + if not resolved_model: + raise ValueError("Django did not return a model for " + "{0}.{1}".format(app_name, model_name)) + return resolved_model elif inspect.isclass(obj) and issubclass(obj, models.Model): return obj raise ValueError("{0} is not a Django model".format(obj)) diff --git a/tests/test_utils.py b/tests/test_utils.py index 96c5f997..0bdb36bb 100644 --- a/tests/test_utils.py +++ b/tests/test_utils.py @@ -7,6 +7,8 @@ from rest_framework.utils.breadcrumbs import get_breadcrumbs from rest_framework.views import APIView from tests.models import BasicModel +import rest_framework.utils.model_meta + class Root(APIView): pass @@ -130,3 +132,34 @@ class ResolveModelTests(TestCase): def test_resolve_improper_string_representation(self): with self.assertRaises(ValueError): _resolve_model('BasicModel') + + +class ResolveModelWithPatchedDjangoTests(TestCase): + """ + Test coverage for when Django's `get_model` returns `None`. + + Under certain circumstances Django may return `None` with `get_model`: + http://git.io/get-model-source + + It usually happens with circular imports so it is important that DRF + excepts early, otherwise fault happens downstream and is much more + difficult to debug. + + """ + + def setUp(self): + """Monkeypatch get_model.""" + self.get_model = rest_framework.utils.model_meta.models.get_model + + def get_model(app_label, model_name): + return None + + rest_framework.utils.model_meta.models.get_model = get_model + + def tearDown(self): + """Revert monkeypatching.""" + rest_framework.utils.model_meta.models.get_model = self.get_model + + def test_blows_up_if_model_does_not_resolve(self): + with self.assertRaises(ValueError): + _resolve_model('tests.BasicModel') |