Improve test client type stubs (#322)

* Added missing `follow: bool` argument to Client request methods.
* Annotated return types as `HttpResponse` instead of `Any`.
* Made `Client` class inherit from `RequestFactory`, as it does in Django.
* Changed `json()` return type to Any, as it can also be a list.

Wrt (2), these return types were reverted from `HttpResponse` to `Any`
in commit 287c64d6fb. But I suspect that
was simply to silence mypy warnings about "incompatible with supertype
RequestFactory", not because there were any issues with the annotation.

Note that `Client.request()` monkey-patches the `HttpResponse` object
with some additional attributes. Those attributes were already annotated
before, I reordered and added additional comments to make it clear where
they come from.

django-stubs/http/response.pyi

@@ -62,25 +62,27 @@ class HttpResponseBase(Iterable[Any]):
     def __iter__(self) -> Iterator[Any]: ...
 
 class HttpResponse(HttpResponseBase):
-    client: Client
-    context: Context
     content: Any
     csrf_cookie_set: bool
     redirect_chain: List[Tuple[str, int]]
-    request: Dict[str, Any]
-    resolver_match: ResolverMatch
     sameorigin: bool
-    templates: List[Template]
     test_server_port: str
     test_was_secure_request: bool
-    wsgi_request: WSGIRequest
     xframe_options_exempt: bool
     streaming: bool = ...
     def __init__(self, content: object = ..., *args: Any, **kwargs: Any) -> None: ...
     def serialize(self) -> bytes: ...
     @property
     def url(self) -> str: ...
-    def json(self) -> Dict[str, Any]: ...
+    # Attributes assigned by monkey-patching in test client ClientHandler.__call__()
+    wsgi_request: WSGIRequest
+    # Attributes assigned by monkey-patching in test client Client.request()
+    client: Client
+    request: Dict[str, Any]
+    templates: List[Template]
+    context: Context
+    resolver_match: ResolverMatch
+    def json(self) -> Any: ...
 
 class StreamingHttpResponse(HttpResponseBase):
     content: Any

django-stubs/test/client.pyi

@@ -1,15 +1,16 @@
 from io import BytesIO
+from types import TracebackType
 from typing import Any, Dict, List, Optional, Pattern, Tuple, Type, Union
 
 from django.contrib.auth.models import AbstractUser
 from django.contrib.sessions.backends.base import SessionBase
 from django.core.handlers.base import BaseHandler
-from django.core.serializers.json import DjangoJSONEncoder
 from django.http.cookie import SimpleCookie
 from django.http.request import HttpRequest
 from django.http.response import HttpResponse, HttpResponseBase
 
 from django.core.handlers.wsgi import WSGIRequest
+from json import JSONEncoder
 
 BOUNDARY: str = ...
 MULTIPART_CONTENT: str = ...
@@ -37,11 +38,11 @@ def encode_multipart(boundary: str, data: Dict[str, Any]) -> bytes: ...
 def encode_file(boundary: str, key: str, file: Any) -> List[bytes]: ...
 
 class RequestFactory:
-    json_encoder: Type[DjangoJSONEncoder] = ...
-    defaults: Dict[str, str] = ...
-    cookies: SimpleCookie = ...
-    errors: BytesIO = ...
-    def __init__(self, *, json_encoder: Any = ..., **defaults: Any) -> None: ...
+    json_encoder: Type[JSONEncoder]
+    defaults: Dict[str, str]
+    cookies: SimpleCookie
+    errors: BytesIO
+    def __init__(self, *, json_encoder: Type[JSONEncoder] = ..., **defaults: Any) -> None: ...
     def request(self, **request: Any) -> WSGIRequest: ...
     def get(self, path: str, data: Any = ..., secure: bool = ..., **extra: Any) -> WSGIRequest: ...
     def post(
@@ -54,6 +55,7 @@ class RequestFactory:
         path: str,
         data: Union[Dict[str, str], str] = ...,
         content_type: str = ...,
+        follow: bool = ...,
         secure: bool = ...,
         **extra: Any
     ) -> WSGIRequest: ...
@@ -76,39 +78,50 @@ class RequestFactory:
         **extra: Any
     ) -> WSGIRequest: ...
 
-class Client:
-    json_encoder: Type[DjangoJSONEncoder] = ...
-    defaults: Dict[str, str] = ...
-    cookies: SimpleCookie = ...
-    errors: BytesIO = ...
-    handler: ClientHandler = ...
-    exc_info: None = ...
-    def __init__(self, enforce_csrf_checks: bool = ..., **defaults: Any) -> None: ...
-    def request(self, **request: Any) -> Any: ...
-    def get(self, path: str, data: Any = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def post(self, path: str, data: Any = ..., content_type: str = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def head(self, path: str, data: Any = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def trace(self, path: str, secure: bool = ..., **extra: Any) -> Any: ...
-    def options(
+class Client(RequestFactory):
+    handler: ClientHandler
+    raise_request_exception: bool
+    exc_info: Optional[Tuple[Type[BaseException], BaseException, TracebackType]]
+    def __init__(
+        self,
+        enforce_csrf_checks: bool = ...,
+        raise_request_exception: bool = ...,
+        *,
+        json_encoder: Type[JSONEncoder] = ...,
+        **defaults: Any
+    ) -> None: ...
+    # Silence type warnings, since this class overrides arguments and return types in an unsafe manner.
+    def request(self, **request: Any) -> HttpResponse: ...  # type: ignore
+    def get(  # type: ignore
+        self, path: str, data: Any = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def post(  # type: ignore
+        self, path: str, data: Any = ..., content_type: str = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def head(  # type: ignore
+        self, path: str, data: Any = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def trace(  # type: ignore
+        self, path: str, follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def options(  # type: ignore
         self,
         path: str,
         data: Union[Dict[str, str], str] = ...,
         content_type: str = ...,
+        follow: bool = ...,
         secure: bool = ...,
         **extra: Any
-    ) -> Any: ...
-    def put(self, path: str, data: Any = ..., content_type: str = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def patch(self, path: str, data: Any = ..., content_type: str = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def delete(self, path: str, data: Any = ..., content_type: str = ..., secure: bool = ..., **extra: Any) -> Any: ...
-    def generic(
-        self,
-        method: str,
-        path: str,
-        data: Any = ...,
-        content_type: Optional[str] = ...,
-        secure: bool = ...,
-        **extra: Any
-    ) -> Any: ...
+    ) -> HttpResponse: ...  # type: ignore
+    def put(  # type: ignore
+        self, path: str, data: Any = ..., content_type: str = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def patch(  # type: ignore
+        self, path: str, data: Any = ..., content_type: str = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
+    def delete(  # type: ignore
+        self, path: str, data: Any = ..., content_type: str = ..., follow: bool = ..., secure: bool = ..., **extra: Any
+    ) -> HttpResponse: ...  # type: ignore
     def store_exc_info(self, **kwargs: Any) -> None: ...
     @property
     def session(self) -> SessionBase: ...

scripts/enabled_test_modules.py

@@ -64,7 +64,12 @@ IGNORED_ERRORS = {
         'Incompatible types in string interpolation',
         '"None" has no attribute',
         'has no attribute "assert',
-        'Unsupported dynamic base class'
+        'Unsupported dynamic base class',
+        'error: "HttpResponse" has no attribute "streaming_content"',
+        'error: "HttpResponse" has no attribute "context_data"',
+    ],
+    'admin_inlines': [
+        'error: "HttpResponse" has no attribute "rendered_content"',
     ],
     'admin_utils': [
         '"Article" has no attribute "non_field"',
@@ -240,6 +245,7 @@ IGNORED_ERRORS = {
     ],
     'middleware': [
         re.compile(r'"(HttpRequest|WSGIRequest)" has no attribute'),
+        'Incompatible types in assignment (expression has type "HttpResponseBase", variable has type "HttpResponse")',
     ],
     'many_to_many': [
         '(expression has type "List[Article]", variable has type "Article_RelatedManager2',
@@ -376,6 +382,9 @@ IGNORED_ERRORS = {
     'settings_tests': [
         'Argument 1 to "Settings" has incompatible type "Optional[str]"; expected "str"'
     ],
+    'shortcuts': [
+        'error: "Context" has no attribute "request"',
+    ],
     'signals': [
         'Argument 1 to "append" of "list" has incompatible type "Tuple[Any, Any, Optional[Any], Any]";'
     ],
@@ -428,6 +437,7 @@ IGNORED_ERRORS = {
     'test_client_regress': [
         '(expression has type "Dict[<nothing>, <nothing>]", variable has type "SessionBase")',
         'Unsupported left operand type for + ("None")',
+        'Argument 1 to "len" has incompatible type "Context"; expected "Sized"',
     ],
     'transactions': [
         'Incompatible types in assignment (expression has type "Thread", variable has type "Callable[[], Any]")'

test-data/typecheck/test/test_testcase.yml

@@ -0,0 +1,12 @@
+-   case: testcase_client_attr
+    main: |
+      from django.test.testcases import TestCase
+
+      class ExampleTestCase(TestCase):
+          def test_method(self) -> None:
+              reveal_type(self.client)  # N: Revealed type is 'django.test.client.Client'
+              resp = self.client.post('/url', {'doit': 'srs'}, 'application/json', False, True, extra='value')
+              reveal_type(resp.status_code)   # N: Revealed type is 'builtins.int'
+              # Attributes monkey-patched by test Client class:
+              resp.json()
+              reveal_type(resp.wsgi_request)  # N: Revealed type is 'django.core.handlers.wsgi.WSGIRequest'