test_generics.py

import sys

import pytest
from django.db import models
from django.http import Http404
from django.shortcuts import get_object_or_404
from django.test import TestCase

from rest_framework import generics, renderers, serializers, status
from rest_framework.exceptions import ErrorDetail
from rest_framework.response import Response
from rest_framework.test import APIRequestFactory
from tests.models import (
    BasicModel, ForeignKeySource, ForeignKeyTarget, RESTFrameworkModel,
    UUIDForeignKeyTarget
)

factory = APIRequestFactory()


# Models
class SlugBasedModel(RESTFrameworkModel):
    text = models.CharField(max_length=100)
    slug = models.SlugField(max_length=32)


# Model for regression test for #285
class Comment(RESTFrameworkModel):
    email = models.EmailField()
    content = models.CharField(max_length=200)
    created = models.DateTimeField(auto_now_add=True)


# Serializers
class BasicSerializer(serializers.ModelSerializer):
    class Meta:
        model = BasicModel
        fields = '__all__'


class ForeignKeySerializer(serializers.ModelSerializer):
    class Meta:
        model = ForeignKeySource
        fields = '__all__'


class SlugSerializer(serializers.ModelSerializer):
    slug = serializers.ReadOnlyField()

    class Meta:
        model = SlugBasedModel
        fields = ('text', 'slug')


# Views
class RootView(generics.ListCreateAPIView):
    queryset = BasicModel.objects.all()
    serializer_class = BasicSerializer


class InstanceView(generics.RetrieveUpdateDestroyAPIView):
    queryset = BasicModel.objects.exclude(text='filtered out')
    serializer_class = BasicSerializer


class FKInstanceView(generics.RetrieveUpdateDestroyAPIView):
    queryset = ForeignKeySource.objects.all()
    serializer_class = ForeignKeySerializer


class SlugBasedInstanceView(InstanceView):
    """
    A model with a slug-field.
    """
    queryset = SlugBasedModel.objects.all()
    serializer_class = SlugSerializer
    lookup_field = 'slug'


# Tests
class TestRootView(TestCase):
    def setUp(self):
        """
        Create 3 BasicModel instances.
        """
        items = ['foo', 'bar', 'baz']
        for item in items:
            BasicModel(text=item).save()
        self.objects = BasicModel.objects
        self.data = [
            {'id': obj.id, 'text': obj.text}
            for obj in self.objects.all()
        ]
        self.view = RootView.as_view()

    def test_get_root_view(self):
        """
        GET requests to ListCreateAPIView should return list of objects.
        """
        request = factory.get('/')
        with self.assertNumQueries(1):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == self.data

    def test_head_root_view(self):
        """
        HEAD requests to ListCreateAPIView should return 200.
        """
        request = factory.head('/')
        with self.assertNumQueries(1):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_200_OK

    def test_post_root_view(self):
        """
        POST requests to ListCreateAPIView should create a new object.
        """
        data = {'text': 'foobar'}
        request = factory.post('/', data, format='json')
        with self.assertNumQueries(1):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_201_CREATED
        assert response.data == {'id': 4, 'text': 'foobar'}
        created = self.objects.get(id=4)
        assert created.text == 'foobar'

    def test_put_root_view(self):
        """
        PUT requests to ListCreateAPIView should not be allowed
        """
        data = {'text': 'foobar'}
        request = factory.put('/', data, format='json')
        with self.assertNumQueries(0):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_405_METHOD_NOT_ALLOWED
        assert response.data == {"detail": 'Method "PUT" not allowed.'}

    def test_delete_root_view(self):
        """
        DELETE requests to ListCreateAPIView should not be allowed
        """
        request = factory.delete('/')
        with self.assertNumQueries(0):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_405_METHOD_NOT_ALLOWED
        assert response.data == {"detail": 'Method "DELETE" not allowed.'}

    def test_post_cannot_set_id(self):
        """
        POST requests to create a new object should not be able to set the id.
        """
        data = {'id': 999, 'text': 'foobar'}
        request = factory.post('/', data, format='json')
        with self.assertNumQueries(1):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_201_CREATED
        assert response.data == {'id': 4, 'text': 'foobar'}
        created = self.objects.get(id=4)
        assert created.text == 'foobar'

    def test_post_error_root_view(self):
        """
        POST requests to ListCreateAPIView in HTML should include a form error.
        """
        data = {'text': 'foobar' * 100}
        request = factory.post('/', data, HTTP_ACCEPT='text/html')
        response = self.view(request).render()
        expected_error = '<span class="help-block">Ensure this field has no more than 100 characters.</span>'
        assert expected_error in response.rendered_content.decode()


EXPECTED_QUERIES_FOR_PUT = 2


class TestInstanceView(TestCase):
    def setUp(self):
        """
        Create 3 BasicModel instances.
        """
        items = ['foo', 'bar', 'baz', 'filtered out']
        for item in items:
            BasicModel(text=item).save()
        self.objects = BasicModel.objects.exclude(text='filtered out')
        self.data = [
            {'id': obj.id, 'text': obj.text}
            for obj in self.objects.all()
        ]
        self.view = InstanceView.as_view()
        self.slug_based_view = SlugBasedInstanceView.as_view()

    def test_get_instance_view(self):
        """
        GET requests to RetrieveUpdateDestroyAPIView should return a single object.
        """
        request = factory.get('/1')
        with self.assertNumQueries(1):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == self.data[0]

    def test_post_instance_view(self):
        """
        POST requests to RetrieveUpdateDestroyAPIView should not be allowed
        """
        data = {'text': 'foobar'}
        request = factory.post('/', data, format='json')
        with self.assertNumQueries(0):
            response = self.view(request).render()
        assert response.status_code == status.HTTP_405_METHOD_NOT_ALLOWED
        assert response.data == {"detail": 'Method "POST" not allowed.'}

    def test_put_instance_view(self):
        """
        PUT requests to RetrieveUpdateDestroyAPIView should update an object.
        """
        data = {'text': 'foobar'}
        request = factory.put('/1', data, format='json')
        with self.assertNumQueries(EXPECTED_QUERIES_FOR_PUT):
            response = self.view(request, pk='1').render()
        assert response.status_code == status.HTTP_200_OK
        assert dict(response.data) == {'id': 1, 'text': 'foobar'}
        updated = self.objects.get(id=1)
        assert updated.text == 'foobar'

    def test_patch_instance_view(self):
        """
        PATCH requests to RetrieveUpdateDestroyAPIView should update an object.
        """
        data = {'text': 'foobar'}
        request = factory.patch('/1', data, format='json')

        with self.assertNumQueries(EXPECTED_QUERIES_FOR_PUT):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == {'id': 1, 'text': 'foobar'}
        updated = self.objects.get(id=1)
        assert updated.text == 'foobar'

    def test_delete_instance_view(self):
        """
        DELETE requests to RetrieveUpdateDestroyAPIView should delete an object.
        """
        request = factory.delete('/1')
        with self.assertNumQueries(2):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_204_NO_CONTENT
        assert response.content == b''
        ids = [obj.id for obj in self.objects.all()]
        assert ids == [2, 3]

    def test_get_instance_view_incorrect_arg(self):
        """
        GET requests with an incorrect pk type, should raise 404, not 500.
        Regression test for #890.
        """
        request = factory.get('/a')
        with self.assertNumQueries(0):
            response = self.view(request, pk='a').render()
        assert response.status_code == status.HTTP_404_NOT_FOUND

    def test_put_cannot_set_id(self):
        """
        PUT requests to create a new object should not be able to set the id.
        """
        data = {'id': 999, 'text': 'foobar'}
        request = factory.put('/1', data, format='json')
        with self.assertNumQueries(EXPECTED_QUERIES_FOR_PUT):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == {'id': 1, 'text': 'foobar'}
        updated = self.objects.get(id=1)
        assert updated.text == 'foobar'

    def test_put_to_deleted_instance(self):
        """
        PUT requests to RetrieveUpdateDestroyAPIView should return 404 if
        an object does not currently exist.
        """
        self.objects.get(id=1).delete()
        data = {'text': 'foobar'}
        request = factory.put('/1', data, format='json')
        with self.assertNumQueries(1):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_404_NOT_FOUND

    def test_put_to_filtered_out_instance(self):
        """
        PUT requests to an URL of instance which is filtered out should not be
        able to create new objects.
        """
        data = {'text': 'foo'}
        filtered_out_pk = BasicModel.objects.filter(text='filtered out')[0].pk
        request = factory.put('/{}'.format(filtered_out_pk), data, format='json')
        response = self.view(request, pk=filtered_out_pk).render()
        assert response.status_code == status.HTTP_404_NOT_FOUND

    def test_patch_cannot_create_an_object(self):
        """
        PATCH requests should not be able to create objects.
        """
        data = {'text': 'foobar'}
        request = factory.patch('/999', data, format='json')
        with self.assertNumQueries(1):
            response = self.view(request, pk=999).render()
        assert response.status_code == status.HTTP_404_NOT_FOUND
        assert not self.objects.filter(id=999).exists()

    def test_put_error_instance_view(self):
        """
        Incorrect PUT requests in HTML should include a form error.
        """
        data = {'text': 'foobar' * 100}
        request = factory.put('/', data, HTTP_ACCEPT='text/html')
        response = self.view(request, pk=1).render()
        expected_error = '<span class="help-block">Ensure this field has no more than 100 characters.</span>'
        assert expected_error in response.rendered_content.decode()


class TestFKInstanceView(TestCase):
    def setUp(self):
        """
        Create 3 BasicModel instances.
        """
        items = ['foo', 'bar', 'baz']
        for item in items:
            t = ForeignKeyTarget(name=item)
            t.save()
            ForeignKeySource(name='source_' + item, target=t).save()

        self.objects = ForeignKeySource.objects
        self.data = [
            {'id': obj.id, 'name': obj.name}
            for obj in self.objects.all()
        ]
        self.view = FKInstanceView.as_view()


class TestOverriddenGetObject(TestCase):
    """
    Test cases for a RetrieveUpdateDestroyAPIView that does NOT use the
    queryset/model mechanism but instead overrides get_object()
    """

    def setUp(self):
        """
        Create 3 BasicModel instances.
        """
        items = ['foo', 'bar', 'baz']
        for item in items:
            BasicModel(text=item).save()
        self.objects = BasicModel.objects
        self.data = [
            {'id': obj.id, 'text': obj.text}
            for obj in self.objects.all()
        ]

        class OverriddenGetObjectView(generics.RetrieveUpdateDestroyAPIView):
            """
            Example detail view for override of get_object().
            """
            serializer_class = BasicSerializer

            def get_object(self):
                pk = int(self.kwargs['pk'])
                return get_object_or_404(BasicModel.objects.all(), id=pk)

        self.view = OverriddenGetObjectView.as_view()

    def test_overridden_get_object_view(self):
        """
        GET requests to RetrieveUpdateDestroyAPIView should return a single object.
        """
        request = factory.get('/1')
        with self.assertNumQueries(1):
            response = self.view(request, pk=1).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == self.data[0]


# Regression test for #285

class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        exclude = ('created',)


class CommentView(generics.ListCreateAPIView):
    serializer_class = CommentSerializer
    model = Comment


class TestCreateModelWithAutoNowAddField(TestCase):
    def setUp(self):
        self.objects = Comment.objects
        self.view = CommentView.as_view()

    def test_create_model_with_auto_now_add_field(self):
        """
        Regression test for #285

        https://github.com/encode/django-rest-framework/issues/285
        """
        data = {'email': 'foobar@example.com', 'content': 'foobar'}
        request = factory.post('/', data, format='json')
        response = self.view(request).render()
        assert response.status_code == status.HTTP_201_CREATED
        created = self.objects.get(id=1)
        assert created.content == 'foobar'


# Test for particularly ugly regression with m2m in browsable API
class ClassB(models.Model):
    name = models.CharField(max_length=255)


class ClassA(models.Model):
    name = models.CharField(max_length=255)
    children = models.ManyToManyField(ClassB, blank=True, null=True)


class ClassASerializer(serializers.ModelSerializer):
    children = serializers.PrimaryKeyRelatedField(
        many=True, queryset=ClassB.objects.all()
    )

    class Meta:
        model = ClassA
        fields = '__all__'


class ExampleView(generics.ListCreateAPIView):
    serializer_class = ClassASerializer
    queryset = ClassA.objects.all()


class TestM2MBrowsableAPI(TestCase):
    def test_m2m_in_browsable_api(self):
        """
        Test for particularly ugly regression with m2m in browsable API
        """
        request = factory.get('/', HTTP_ACCEPT='text/html')
        view = ExampleView().as_view()
        response = view(request).render()
        assert response.status_code == status.HTTP_200_OK


class InclusiveFilterBackend:
    def filter_queryset(self, request, queryset, view):
        return queryset.filter(text='foo')


class ExclusiveFilterBackend:
    def filter_queryset(self, request, queryset, view):
        return queryset.filter(text='other')


class TwoFieldModel(models.Model):
    field_a = models.CharField(max_length=100)
    field_b = models.CharField(max_length=100)


class DynamicSerializerView(generics.ListCreateAPIView):
    queryset = TwoFieldModel.objects.all()
    renderer_classes = (renderers.BrowsableAPIRenderer, renderers.JSONRenderer)

    def get_serializer_class(self):
        if self.request.method == 'POST':
            class DynamicSerializer(serializers.ModelSerializer):
                class Meta:
                    model = TwoFieldModel
                    fields = ('field_b',)
        else:
            class DynamicSerializer(serializers.ModelSerializer):
                class Meta:
                    model = TwoFieldModel
                    fields = '__all__'
        return DynamicSerializer


class TestFilterBackendAppliedToViews(TestCase):
    def setUp(self):
        """
        Create 3 BasicModel instances to filter on.
        """
        items = ['foo', 'bar', 'baz']
        for item in items:
            BasicModel(text=item).save()
        self.objects = BasicModel.objects
        self.data = [
            {'id': obj.id, 'text': obj.text}
            for obj in self.objects.all()
        ]

    def test_get_root_view_filters_by_name_with_filter_backend(self):
        """
        GET requests to ListCreateAPIView should return filtered list.
        """
        root_view = RootView.as_view(filter_backends=(InclusiveFilterBackend,))
        request = factory.get('/')
        response = root_view(request).render()
        assert response.status_code == status.HTTP_200_OK
        assert len(response.data) == 1
        assert response.data == [{'id': 1, 'text': 'foo'}]

    def test_get_root_view_filters_out_all_models_with_exclusive_filter_backend(self):
        """
        GET requests to ListCreateAPIView should return empty list when all models are filtered out.
        """
        root_view = RootView.as_view(filter_backends=(ExclusiveFilterBackend,))
        request = factory.get('/')
        response = root_view(request).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == []

    def test_get_instance_view_filters_out_name_with_filter_backend(self):
        """
        GET requests to RetrieveUpdateDestroyAPIView should raise 404 when model filtered out.
        """
        instance_view = InstanceView.as_view(filter_backends=(ExclusiveFilterBackend,))
        request = factory.get('/1')
        response = instance_view(request, pk=1).render()
        assert response.status_code == status.HTTP_404_NOT_FOUND
        assert response.data == {
            'detail': ErrorDetail(
                string='No BasicModel matches the given query.',
                code='not_found'
            )
        }

    def test_get_instance_view_will_return_single_object_when_filter_does_not_exclude_it(self):
        """
        GET requests to RetrieveUpdateDestroyAPIView should return a single object when not excluded
        """
        instance_view = InstanceView.as_view(filter_backends=(InclusiveFilterBackend,))
        request = factory.get('/1')
        response = instance_view(request, pk=1).render()
        assert response.status_code == status.HTTP_200_OK
        assert response.data == {'id': 1, 'text': 'foo'}

    def test_dynamic_serializer_form_in_browsable_api(self):
        """
        GET requests to ListCreateAPIView should return filtered list.
        """
        view = DynamicSerializerView.as_view()
        request = factory.get('/')
        response = view(request).render()
        content = response.content.decode()
        assert 'field_b' in content
        assert 'field_a' not in content


class TestGuardedQueryset(TestCase):
    def test_guarded_queryset(self):
        class QuerysetAccessError(generics.ListAPIView):
            queryset = BasicModel.objects.all()

            def get(self, request):
                return Response(list(self.queryset))

        view = QuerysetAccessError.as_view()
        request = factory.get('/')
        with pytest.raises(RuntimeError):
            view(request).render()


class ApiViewsTests(TestCase):

    def test_create_api_view_post(self):
        class MockCreateApiView(generics.CreateAPIView):
            def create(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockCreateApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.post('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_destroy_api_view_delete(self):
        class MockDestroyApiView(generics.DestroyAPIView):
            def destroy(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockDestroyApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.delete('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_update_api_view_partial_update(self):
        class MockUpdateApiView(generics.UpdateAPIView):
            def partial_update(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockUpdateApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.patch('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_retrieve_update_api_view_get(self):
        class MockRetrieveUpdateApiView(generics.RetrieveUpdateAPIView):
            def retrieve(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockRetrieveUpdateApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.get('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_retrieve_update_api_view_put(self):
        class MockRetrieveUpdateApiView(generics.RetrieveUpdateAPIView):
            def update(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockRetrieveUpdateApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.put('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_retrieve_update_api_view_patch(self):
        class MockRetrieveUpdateApiView(generics.RetrieveUpdateAPIView):
            def partial_update(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockRetrieveUpdateApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.patch('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_retrieve_destroy_api_view_get(self):
        class MockRetrieveDestroyUApiView(generics.RetrieveDestroyAPIView):
            def retrieve(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockRetrieveDestroyUApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.get('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data

    def test_retrieve_destroy_api_view_delete(self):
        class MockRetrieveDestroyUApiView(generics.RetrieveDestroyAPIView):
            def destroy(self, request, *args, **kwargs):
                self.called = True
                self.call_args = (request, args, kwargs)
        view = MockRetrieveDestroyUApiView()
        data = ('test request', ('test arg',), {'test_kwarg': 'test'})
        view.delete('test request', 'test arg', test_kwarg='test')
        assert view.called is True
        assert view.call_args == data


class GetObjectOr404Tests(TestCase):
    def setUp(self):
        super().setUp()
        self.uuid_object = UUIDForeignKeyTarget.objects.create(name='bar')

    def test_get_object_or_404_with_valid_uuid(self):
        obj = generics.get_object_or_404(
            UUIDForeignKeyTarget, pk=self.uuid_object.pk
        )
        assert obj == self.uuid_object

    def test_get_object_or_404_with_invalid_string_for_uuid(self):
        with pytest.raises(Http404):
            generics.get_object_or_404(UUIDForeignKeyTarget, pk='not-a-uuid')


class TestSerializer(TestCase):

    def test_serializer_class_not_provided(self):
        class NoSerializerClass(generics.GenericAPIView):
            pass

        with pytest.raises(AssertionError) as excinfo:
            NoSerializerClass().get_serializer_class()

        assert str(excinfo.value) == (
            "'NoSerializerClass' should either include a `serializer_class` "
            "attribute, or override the `get_serializer_class()` method.")

    def test_given_context_not_overridden(self):
        context = object()

        class View(generics.ListAPIView):
            serializer_class = serializers.Serializer

            def list(self, request):
                response = Response()
                response.serializer = self.get_serializer(context=context)
                return response

        response = View.as_view()(factory.get('/'))
        serializer = response.serializer

        assert serializer.context is context


class TestTyping(TestCase):
    @pytest.mark.skipif(
        sys.version_info < (3, 7),
        reason="subscriptable classes requires Python 3.7 or higher",
    )
    def test_genericview_is_subscriptable(self):
        assert generics.GenericAPIView is generics.GenericAPIView["foo"]

    @pytest.mark.skipif(
        sys.version_info < (3, 7),
        reason="subscriptable classes requires Python 3.7 or higher",
    )
    def test_listview_is_subscriptable(self):
        assert generics.ListAPIView is generics.ListAPIView["foo"]

    @pytest.mark.skipif(
        sys.version_info < (3, 7),
        reason="subscriptable classes requires Python 3.7 or higher",
    )
    def test_instanceview_is_subscriptable(self):
        assert generics.RetrieveAPIView is generics.RetrieveAPIView["foo"]