django-rest-framework/tests/test_serializer.py

# coding: utf-8
from __future__ import unicode_literals

import pickle

import pytest

from rest_framework import serializers
from rest_framework.compat import unicode_repr

from .utils import MockObject


# Tests for core functionality.
# -----------------------------

class TestSerializer:
    def setup(self):
        class ExampleSerializer(serializers.Serializer):
            char = serializers.CharField()
            integer = serializers.IntegerField()
        self.Serializer = ExampleSerializer

    def test_valid_serializer(self):
        serializer = self.Serializer(data={'char': 'abc', 'integer': 123})
        assert serializer.is_valid()
        assert serializer.validated_data == {'char': 'abc', 'integer': 123}
        assert serializer.errors == {}

    def test_invalid_serializer(self):
        serializer = self.Serializer(data={'char': 'abc'})
        assert not serializer.is_valid()
        assert serializer.validated_data == {}
        assert serializer.errors == {'integer': ['This field is required.']}

    def test_partial_validation(self):
        serializer = self.Serializer(data={'char': 'abc'}, partial=True)
        assert serializer.is_valid()
        assert serializer.validated_data == {'char': 'abc'}
        assert serializer.errors == {}

    def test_empty_serializer(self):
        serializer = self.Serializer()
        assert serializer.data == {'char': '', 'integer': None}

    def test_missing_attribute_during_serialization(self):
        class MissingAttributes:
            pass
        instance = MissingAttributes()
        serializer = self.Serializer(instance)
        with pytest.raises(AttributeError):
            serializer.data

    def test_data_access_before_save_raises_error(self):
        def create(validated_data):
            return validated_data
        serializer = self.Serializer(data={'char': 'abc', 'integer': 123})
        serializer.create = create
        assert serializer.is_valid()
        assert serializer.data == {'char': 'abc', 'integer': 123}
        with pytest.raises(AssertionError):
            serializer.save()


class TestValidateMethod:
    def test_non_field_error_validate_method(self):
        class ExampleSerializer(serializers.Serializer):
            char = serializers.CharField()
            integer = serializers.IntegerField()

            def validate(self, attrs):
                raise serializers.ValidationError('Non field error')

        serializer = ExampleSerializer(data={'char': 'abc', 'integer': 123})
        assert not serializer.is_valid()
        assert serializer.errors == {'non_field_errors': ['Non field error']}

    def test_field_error_validate_method(self):
        class ExampleSerializer(serializers.Serializer):
            char = serializers.CharField()
            integer = serializers.IntegerField()

            def validate(self, attrs):
                raise serializers.ValidationError({'char': 'Field error'})

        serializer = ExampleSerializer(data={'char': 'abc', 'integer': 123})
        assert not serializer.is_valid()
        assert serializer.errors == {'char': ['Field error']}


class TestBaseSerializer:
    def setup(self):
        class ExampleSerializer(serializers.BaseSerializer):
            def to_representation(self, obj):
                return {
                    'id': obj['id'],
                    'email': obj['name'] + '@' + obj['domain']
                }

            def to_internal_value(self, data):
                name, domain = str(data['email']).split('@')
                return {
                    'id': int(data['id']),
                    'name': name,
                    'domain': domain,
                }

        self.Serializer = ExampleSerializer

    def test_serialize_instance(self):
        instance = {'id': 1, 'name': 'tom', 'domain': 'example.com'}
        serializer = self.Serializer(instance)
        assert serializer.data == {'id': 1, 'email': 'tom@example.com'}

    def test_serialize_list(self):
        instances = [
            {'id': 1, 'name': 'tom', 'domain': 'example.com'},
            {'id': 2, 'name': 'ann', 'domain': 'example.com'},
        ]
        serializer = self.Serializer(instances, many=True)
        assert serializer.data == [
            {'id': 1, 'email': 'tom@example.com'},
            {'id': 2, 'email': 'ann@example.com'}
        ]

    def test_validate_data(self):
        data = {'id': 1, 'email': 'tom@example.com'}
        serializer = self.Serializer(data=data)
        assert serializer.is_valid()
        assert serializer.validated_data == {
            'id': 1,
            'name': 'tom',
            'domain': 'example.com'
        }

    def test_validate_list(self):
        data = [
            {'id': 1, 'email': 'tom@example.com'},
            {'id': 2, 'email': 'ann@example.com'},
        ]
        serializer = self.Serializer(data=data, many=True)
        assert serializer.is_valid()
        assert serializer.validated_data == [
            {'id': 1, 'name': 'tom', 'domain': 'example.com'},
            {'id': 2, 'name': 'ann', 'domain': 'example.com'}
        ]


class TestStarredSource:
    """
    Tests for `source='*'` argument, which is used for nested representations.

    For example:

        nested_field = NestedField(source='*')
    """
    data = {
        'nested1': {'a': 1, 'b': 2},
        'nested2': {'c': 3, 'd': 4}
    }

    def setup(self):
        class NestedSerializer1(serializers.Serializer):
            a = serializers.IntegerField()
            b = serializers.IntegerField()

        class NestedSerializer2(serializers.Serializer):
            c = serializers.IntegerField()
            d = serializers.IntegerField()

        class TestSerializer(serializers.Serializer):
            nested1 = NestedSerializer1(source='*')
            nested2 = NestedSerializer2(source='*')

        self.Serializer = TestSerializer

    def test_nested_validate(self):
        """
        A nested representation is validated into a flat internal object.
        """
        serializer = self.Serializer(data=self.data)
        assert serializer.is_valid()
        assert serializer.validated_data == {
            'a': 1,
            'b': 2,
            'c': 3,
            'd': 4
        }

    def test_nested_serialize(self):
        """
        An object can be serialized into a nested representation.
        """
        instance = {'a': 1, 'b': 2, 'c': 3, 'd': 4}
        serializer = self.Serializer(instance)
        assert serializer.data == self.data


class TestIncorrectlyConfigured:
    def test_incorrect_field_name(self):
        class ExampleSerializer(serializers.Serializer):
            incorrect_name = serializers.IntegerField()

        class ExampleObject:
            def __init__(self):
                self.correct_name = 123

        instance = ExampleObject()
        serializer = ExampleSerializer(instance)
        with pytest.raises(AttributeError) as exc_info:
            serializer.data
        msg = str(exc_info.value)
        assert msg.startswith(
            "Got AttributeError when attempting to get a value for field `incorrect_name` on serializer `ExampleSerializer`.\n"
            "The serializer field might be named incorrectly and not match any attribute or key on the `ExampleObject` instance.\n"
            "Original exception text was:"
        )


class TestUnicodeRepr:
    def test_unicode_repr(self):
        class ExampleSerializer(serializers.Serializer):
            example = serializers.CharField()

        class ExampleObject:
            def __init__(self):
                self.example = '한국'

            def __repr__(self):
                return unicode_repr(self.example)

        instance = ExampleObject()
        serializer = ExampleSerializer(instance)
        repr(serializer)  # Should not error.


class TestNotRequiredOutput:
    def test_not_required_output_for_dict(self):
        """
        'required=False' should allow a dictionary key to be missing in output.
        """
        class ExampleSerializer(serializers.Serializer):
            omitted = serializers.CharField(required=False)
            included = serializers.CharField()

        serializer = ExampleSerializer(data={'included': 'abc'})
        serializer.is_valid()
        assert serializer.data == {'included': 'abc'}

    def test_not_required_output_for_object(self):
        """
        'required=False' should allow an object attribute to be missing in output.
        """
        class ExampleSerializer(serializers.Serializer):
            omitted = serializers.CharField(required=False)
            included = serializers.CharField()

            def create(self, validated_data):
                return MockObject(**validated_data)

        serializer = ExampleSerializer(data={'included': 'abc'})
        serializer.is_valid()
        serializer.save()
        assert serializer.data == {'included': 'abc'}

    def test_default_required_output_for_dict(self):
        """
        'default="something"' should require dictionary key.

        We need to handle this as the field will have an implicit
        'required=False', but it should still have a value.
        """
        class ExampleSerializer(serializers.Serializer):
            omitted = serializers.CharField(default='abc')
            included = serializers.CharField()

        serializer = ExampleSerializer({'included': 'abc'})
        with pytest.raises(KeyError):
            serializer.data

    def test_default_required_output_for_object(self):
        """
        'default="something"' should require object attribute.

        We need to handle this as the field will have an implicit
        'required=False', but it should still have a value.
        """
        class ExampleSerializer(serializers.Serializer):
            omitted = serializers.CharField(default='abc')
            included = serializers.CharField()

        instance = MockObject(included='abc')
        serializer = ExampleSerializer(instance)
        with pytest.raises(AttributeError):
            serializer.data


class TestCacheSerializerData:
    def test_cache_serializer_data(self):
        """
        Caching serializer data with pickle will drop the serializer info,
        but does preserve the data itself.
        """
        class ExampleSerializer(serializers.Serializer):
            field1 = serializers.CharField()
            field2 = serializers.CharField()

        serializer = ExampleSerializer({'field1': 'a', 'field2': 'b'})
        pickled = pickle.dumps(serializer.data)
        data = pickle.loads(pickled)
        assert data == {'field1': 'a', 'field2': 'b'}