Add AttrsInstance protocol to forgotten attrs.asdict and attrs.astuple (

#1090)

* Add AttrsInstance protocol to forgotten attrs.asdict and attrs.astuple

* Add mypy test for attrs.asdict

* Add changelog entry for attrs.asdict

* Clarify it's about type stubs

Co-authored-by: Hynek Schlawack <hs@ox.cx>

changelog.d/1090.change.md

@@ -0,0 +1 @@
+`attrs.asdict()`'s and `attrs.astuple()`'s type stubs now accept the `attrs.AttrsInstance` protocol.

src/attrs/__init__.pyi

@@ -46,7 +46,7 @@ from attr import validators as validators
 
 # TODO: see definition of attr.asdict/astuple
 def asdict(
-    inst: Any,
+    inst: AttrsInstance,
     recurse: bool = ...,
     filter: Optional[_FilterType[Any]] = ...,
     dict_factory: Type[Mapping[Any, Any]] = ...,
@@ -59,7 +59,7 @@ def asdict(
 
 # TODO: add support for returning NamedTuple from the mypy plugin
 def astuple(
-    inst: Any,
+    inst: AttrsInstance,
     recurse: bool = ...,
     filter: Optional[_FilterType[Any]] = ...,
     tuple_factory: Type[Sequence[Any]] = ...,

tests/test_mypy.yml

@@ -1372,6 +1372,25 @@
 
     fields(A)  # E: Argument 1 to "fields" has incompatible type "Type[A]"; expected "Type[AttrsInstance]"  [arg-type]
 
+- case: testAsDict
+  main: |
+    from attrs import asdict, define
+
+    @define
+    class A:
+      a: int
+
+    asdict(A(1))
+
+- case: testAsDictError
+  main: |
+    from attrs import asdict
+
+    class A:
+      a: int
+
+    asdict(A())  # E: Argument 1 to "asdict" has incompatible type "A"; expected "AttrsInstance"  [arg-type]
+
 - case: testHasTypeGuard
   main: |
     from attrs import define, has