Merge pull request #683 from dbrgn/serializer_exception_msg

Improved exception message for missing serializer model meta option

rest_framework/serializers.py

@@ -424,6 +424,8 @@ class ModelSerializer(Serializer):
         """
 
         cls = self.opts.model
+        assert cls is not None, \
+                "Serializer class '%s' is missing 'model' Meta option" % self.__class__.__name__
         opts = get_concrete_model(cls)._meta
         pk_field = opts.pk
         # while pk_field.rel:

rest_framework/tests/serializer.py

@@ -91,6 +91,11 @@ class PositiveIntegerAsChoiceSerializer(serializers.ModelSerializer):
         fields = ['some_integer']
 
 
+class BrokenModelSerializer(serializers.ModelSerializer):
+    class Meta:
+        fields = ['some_field']
+
+
 class BasicTests(TestCase):
     def setUp(self):
         self.comment = Comment(
@@ -353,6 +358,18 @@ class ValidationTests(TestCase):
 
         self.assertIn('created', serializer.errors)
 
+    def test_missing_model_field_exception_msg(self):
+        """
+        Assert that a meaningful exception message is outputted when the model
+        field is missing (e.g. when mistyping ``model``).
+        """
+        try:
+            serializer = BrokenModelSerializer()
+        except AssertionError as e:
+            self.assertEquals(e.args[0], "Serializer class 'BrokenModelSerializer' is missing 'model' Meta option")
+        except:
+            self.fail('Wrong exception type thrown.')
+
 
 class CustomValidationTests(TestCase):
     class CommentSerializerWithFieldValidator(CommentSerializer):