Fix upper bound for Self

python · ilevkivskyi · Nov 15, 2022 · Nov 7, 2022 · Nov 7, 2022 · Nov 7, 2022
commit 362d84a84ac63a11907e91ff960aabb2bcde71e9
diff --git a/docs/source/more_types.rst b/docs/source/more_types.rst
@@ -804,9 +804,10 @@ classes are generic, self-type allows giving them precise signatures:
 .. code-block:: python
 
    T = TypeVar('T')
-   Q = TypeVar('Q', bound='Base[Any]')
 
    class Base(Generic[T]):
+       Q = TypeVar('Q', bound='Base[T]')
+
        def __init__(self, item: T) -> None:
            self.item = item
 

diff --git a/mypy/semanal.py b/mypy/semanal.py
@@ -274,7 +274,7 @@
     invalid_recursive_alias,
     is_named_instance,
 )
-from mypy.typevars import fill_typevars, fill_typevars_with_any
+from mypy.typevars import fill_typevars
 from mypy.util import (
     correct_relative_import,
     is_dunder,
@@ -1041,7 +1041,7 @@ def setup_self_type(self) -> None:
             f"{info.fullname}.Self",
             self.tvar_scope.new_unique_func_id(),
             [],
-            fill_typevars_with_any(info),
+            fill_typevars(info),
         )
 
     def visit_overloaded_func_def(self, defn: OverloadedFuncDef) -> None:

diff --git a/test-data/unit/check-selftype.test b/test-data/unit/check-selftype.test
@@ -1418,7 +1418,7 @@ class C(Generic[T]):
     def __init__(self, val: T) -> None: ...
     @classmethod
     def pair(cls, val: T) -> Tuple[Self, Self]:
-        return (cls(val), C(val))  # E: Incompatible return value type (got "Tuple[Self, C[Any]]", expected "Tuple[Self, Self]")
+        return (cls(val), C(val))  # E: Incompatible return value type (got "Tuple[Self, C[T]]", expected "Tuple[Self, Self]")
 
 class D(C[int]): pass
 reveal_type(C.pair(42))  # N: Revealed type is "Tuple[__main__.C[builtins.int], __main__.C[builtins.int]]"
@@ -1600,3 +1600,13 @@ class C(Generic[T]):
 def test(x: C[T]) -> T:
     reveal_type(x.val)  # N: Revealed type is "T`-1"
     return x.val
+
+[case testTypingSelfGenericBound]
+from typing import Self, Generic, TypeVar
+
+T = TypeVar("T")
+class C(Generic[T]):
+    val: T
+    def foo(self) -> Self:
+        reveal_type(self.val)  # N: Revealed type is "T`1"
+        return self