Preserve callable type in view decorators (#67)

Author: maciej-gol

django-stubs/views/decorators/cache.pyi

@@ -1,5 +1,7 @@
-from typing import Any, Callable, Optional
+from typing import Any, Callable, Optional, TypeVar
+
+_F = TypeVar("_F", bound=Callable[..., Any])
 
 def cache_page(timeout: float, *, cache: Optional[Any] = ..., key_prefix: Optional[Any] = ...) -> Callable: ...
 def cache_control(**kwargs: Any) -> Callable: ...
-def never_cache(view_func: Callable) -> Callable: ...
+def never_cache(view_func: _F) -> _F: ...

django-stubs/views/decorators/clickjacking.pyi

@@ -1,5 +1,7 @@
-from typing import Callable
+from typing import Callable, TypeVar, Any
 
-def xframe_options_deny(view_func: Callable) -> Callable: ...
-def xframe_options_sameorigin(view_func: Callable) -> Callable: ...
-def xframe_options_exempt(view_func: Callable) -> Callable: ...
+_F = TypeVar("_F", bound=Callable[..., Any])
+
+def xframe_options_deny(view_func: _F) -> _F: ...
+def xframe_options_sameorigin(view_func: _F) -> _F: ...
+def xframe_options_exempt(view_func: _F) -> _F: ...

django-stubs/views/decorators/csrf.pyi

@@ -1,4 +1,4 @@
-from typing import Any, Callable
+from typing import Any, Callable, TypeVar
 
 from django.middleware.csrf import CsrfViewMiddleware
 
@@ -14,4 +14,6 @@ class _EnsureCsrfCookie(CsrfViewMiddleware):
 
 ensure_csrf_cookie: Any
 
-def csrf_exempt(view_func: Callable) -> Callable: ...
+_F = TypeVar("_F", bound=Callable[..., Any])
+
+def csrf_exempt(view_func: _F) -> _F: ...

django-stubs/views/decorators/gzip.pyi

@@ -1,5 +1,5 @@
-from typing import Callable, TypeVar
+from typing import Callable, TypeVar, Any
 
-_C = TypeVar("_C", bound=Callable)
+_C = TypeVar("_C", bound=Callable[..., Any])
 
 def gzip_page(view_func: _C) -> _C: ...

django-stubs/views/decorators/http.pyi

@@ -1,4 +1,4 @@
-from typing import Any, Callable, List, Optional
+from typing import Any, Callable, List, Optional, TypeVar
 
 conditional_page: Any
 
@@ -8,6 +8,8 @@ require_GET: Any
 require_POST: Any
 require_safe: Any
 
+_F = TypeVar("_F", bound=Callable[..., Any])
+
 def condition(etag_func: Optional[Callable] = ..., last_modified_func: Optional[Callable] = ...) -> Callable: ...
-def etag(etag_func: Callable) -> Callable: ...
-def last_modified(last_modified_func: Callable) -> Callable: ...
+def etag(etag_func: Callable[..., Any]) -> Callable[[_F], _F]: ...
+def last_modified(last_modified_func: Callable[..., Any]) -> Callable[[_F], _F]: ...

django-stubs/views/decorators/vary.pyi

@@ -1,4 +1,6 @@
-from typing import Any, Callable
+from typing import Any, Callable, TypeVar
+
+_F = TypeVar("_F", bound=Callable[..., Any])
 
 def vary_on_headers(*headers: Any) -> Callable: ...
-def vary_on_cookie(func: Callable) -> Callable: ...
+def vary_on_cookie(func: _F) -> _F: ...