8000 Check superclass compatibility of untyped methods if `--check-untyped… · python/mypy@1af7b2c · GitHub
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sterliakovsterliakov
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Check superclass compatibility of untyped methods if --check-untyped-defs is set (#18970)
This PR enables superclass compatibility checks for untyped methods when `--check-untyped-defs` is set. IMO this behavior is correct as `--check-untyped-defs` is essentially "treat everything as if there were `: Any` annotations on all arguments", hence checking arg count and names is sound. 8000 This PR, however, allows `@override` on classes that have Any fallback as those are often coming from unfollowed imports. This PR started as an attempt to reject `@override` on untyped defs not found in superclass, but I think it's better to just run all compatibility checks if the flag is enabled.
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‎mypy/checker.py

Original file line numberDiff line numberDiff line change
@@ -750,6 +750,9 @@ def _visit_overloaded_func_def(self, defn: OverloadedFuncDef) -> None:
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defn.is_explicit_override
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and not found_method_base_classes
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and found_method_base_classes is not None
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# If the class has Any fallback, we can't be certain that a method
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# is really missing - it might come from unfollowed import.
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and not defn.info.fallback_to_any
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):
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self.msg.no_overridable_method(defn.name, defn)
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self.check_explicit_override_decorator(defn, found_method_base_classes, defn.impl)
@@ -5285,12 +5288,15 @@ def visit_decorator_inner(
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# For overloaded functions/properties we already checked override for overload as a whole.
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if allow_empty or skip_first_item:
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return
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if e.func.info and not e.func.is_dynamic() and not e.is_overload:
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if e.func.info and not e.is_overload:
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found_method_base_classes = self.check_method_override(e)
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if (
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e.func.is_explicit_override
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and not found_method_base_classes
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and found_method_base_classes is not None
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# If the class has Any fallback, we can't be certain that a method
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# is really missing - it might come from unfollowed import.
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and not e.func.info.fallback_to_any
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):
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self.msg.no_overridable_method(e.func.name, e.func)
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self.check_explicit_override_decorator(e.func, found_method_base_classes)
Original file line numberDiff line numberDiff line change
@@ -6651,7 +6651,51 @@ from typing import TypeVar, Tuple, Callable
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T = TypeVar('T')
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def deco(f: Callable[..., T]) -> Callable[..., Tuple[T, int]]: ...
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[builtins fixtures/tuple.pyi]
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[out]
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[case testOverrideWithUntypedNotChecked]
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class Parent:
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def foo(self, x):
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...
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def bar(self, x):
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...
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def baz(self, x: int) -> str:
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return ""
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class Child(Parent):
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def foo(self, y): # OK: names not checked
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...
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def bar(self, x, y):
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...
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def baz(self, x, y):
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return ""
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[builtins fixtures/tuple.pyi]
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[case testOverrideWithUntypedCheckedWithCheckUntypedDefs]
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# flags: --check-untyped-defs
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class Parent:
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def foo(self, x):
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...
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def bar(self, x):
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...
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def baz(self, x: int) -> str:
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return ""
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class Child(Parent):
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def foo(self, y): # OK: names not checked
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...
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def bar(self, x, y) -> None: # E: Signature of "bar" incompatible with supertype "Parent" \
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# N: Superclass: \
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# N: def bar(self, x: Any) -> Any \
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# N: Subclass: \
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# N: def bar(self, x: Any, y: Any) -> None
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...
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def baz(self, x, y): # E: Signature of "baz" incompatible with supertype "Parent" \
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# N: Superclass: \
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# N: def baz(self, x: int) -> str \
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# N: Subclass: \
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# N: def baz(self, x: Any, y: Any) -> Any
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return ""
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[builtins fixtures/tuple.pyi]
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[case testOptionalDescriptorsBinder]
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from typing import Type, TypeVar, Optional
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@@ -3285,6 +3285,39 @@ class C(B):
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def __f(self, y: int) -> str: pass # OK
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[typing fixtures/typing-override.pyi]
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[case testOverrideUntypedDef]
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# flags: --python-version 3.12
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from typing import override
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class Parent: pass
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class Child(Parent):
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@override
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def foo(self, y): pass # E: Method "foo" is marked as an override, but no base method was found with this name
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[typing fixtures/typing-override.pyi]
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[case testOverrideOnUnknownBaseClass]
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# flags: --python-version 3.12
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from typing import overload, override
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from unknown import UnknownParent # type: ignore[import-not-found]
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class UnknownChild(UnknownParent):
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@override
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def foo(self, y): pass # OK
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@override
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def bar(self, y: str) -> None: pass # OK
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@override
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@overload
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def baz(self, y: str) -> None: ...
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@override
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@overload
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def baz(self, y: int) -> None: ...
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def baz(self, y: str | int) -> None: ...
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[typing fixtures/typing-override.pyi]
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[case testCallableProperty]
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from typing import Callable
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