CODEWITHSUNDEEP
pythondjangodjango-rest-framework
binny
binny

Reputation: 729

How is a ValidationError message tested for in Django REST Framework?

When attempting to test data that is passed to a Serializer, I want to test not just for the ValidationError but the error message itself. The way I have it currently checks for the field name in serializer.errors, but I'm looking to test for "Reformat your question please.". What would be a clean way of doing this?

tests.py


class TestQuestionSerializer(TestCase):
    '''Verify that when an invalid question is 
    submitted that a validation error is raised'''

    @classmethod
    def setUpTestData(cls):
        cls.client_data = {
            "invalid": {
                "title": "Can I post a question?"
            },
            "valid": {
                "title": "How can I post a question?"
            }
        }

    def test_question_serializer_fail(self):
        with self.assertRaises(ValidationError) as e:
            serializer = QuestionSerializer(data=self.client_data['invalid'])
            serializer.is_valid(raise_exception=True)
        self.assertIn("title", serializer.errors)

serializers.py

class QuestionSerializer(serializers.Serializer):
    title = serializers.CharField(max_length=50)

    def validate_title(self, value):
        regex = r"^[What|When|Where|How|Why]"
        match = re.search(regex, value)
        if not match:
            raise serializers.ValidationError("Reformat your question please.")
        return value


    def create(self, validated_data):
        return Question.objects.create(**validated_data)

Upvotes: 2

Views: 2483

Answers (1)

gutsytechster
gutsytechster

Reputation: 131

You can use the assertRaisesMessage. Your test will look like this, then

def test_question_serializer_fail(self):
    with self.assertRaisesMessage(ValidationError, "Reformat your question please."):
        serializer = QuestionSerializer(data=self.client_data['invalid'])
        serializer.is_valid(raise_exception=True).

Upvotes: 1

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