PEP 702 (@deprecated): improve the handling of explicit type annotations of assignment statements

mypy/checker.py

@@ -287,6 +287,18 @@ class PartialTypeScope(NamedTuple):
     is_local: bool
 
 
+class InstanceDeprecatedVisitor(TypeTraverserVisitor):
+    """Visitor that recursively checks for deprecations in nested instances."""
+
+    def __init__(self, typechecker: TypeChecker, context: Context) -> None:
+        self.typechecker = typechecker
+        self.context = context
+
+    def visit_instance(self, t: Instance) -> None:
+        super().visit_instance(t)
+        self.typechecker.check_deprecated(t.type, self.context)
+
+
 class TypeChecker(NodeVisitor[None], CheckerPluginInterface):
     """Mypy type checker.
 
@@ -2930,14 +2942,14 @@ def visit_assignment_stmt(self, s: AssignmentStmt) -> None:
         Handle all kinds of assignment statements (simple, indexed, multiple).
         """
 
-        if isinstance(s.rvalue, TempNode) and s.rvalue.no_rhs:
+        if s.unanalyzed_type is not None:
             for lvalue in s.lvalues:
                 if (
                     isinstance(lvalue, NameExpr)
                     and isinstance(var := lvalue.node, Var)
-                    and isinstance(instance := get_proper_type(var.type), Instance)
+                    and (var.type is not None)
                 ):
-                    self.check_deprecated(instance.type, s)
+                    var.type.accept(InstanceDeprecatedVisitor(typechecker=self, context=s))
 
         # Avoid type checking type aliases in stubs to avoid false
         # positives about modern type syntax available in stubs such

test-data/unit/check-deprecated.test

@@ -102,7 +102,8 @@ def h() -> None: ...
 
 [case testDeprecatedClass]
 
-from typing_extensions import deprecated
+from typing import Callable, List, Optional, Tuple, Union
+from typing_extensions import deprecated, TypeAlias, TypeVar
 
 @deprecated("use C2 instead")
 class C: ...
@@ -114,10 +115,40 @@ C.missing()  # N: class __main__.C is deprecated: use C2 instead \
 C.__init__(c)  # N: class __main__.C is deprecated: use C2 instead
 C(1)  # N: class __main__.C is deprecated: use C2 instead \
       # E: Too many arguments for "C"
+
 D = C  # N: class __main__.C is deprecated: use C2 instead
 D()
 t = (C, C, D)  # N: class __main__.C is deprecated: use C2 instead
 
+u1: Union[C, int] = 1  # N: class __main__.C is deprecated: use C2 instead
+u1 = 1
+u2 = 1  # type: Union[C, int]  # N: class __main__.C is deprecated: use C2 instead
+u2 = 1
+
+c1 = c2 = C()  # N: class __main__.C is deprecated: use C2 instead
+i, c3 = 1, C()  # N: class __main__.C is deprecated: use C2 instead
+
+class E: ...
+
+x1: Optional[C]  # N: class __main__.C is deprecated: use C2 instead
+x2: Union[D, C, E]  # N: class __main__.C is deprecated: use C2 instead
+x3: Union[D, Optional[C], E]  # N: class __main__.C is deprecated: use C2 instead
+x4: Tuple[D, C, E]  # N: class __main__.C is deprecated: use C2 instead
+x5: Tuple[Tuple[D, C], E]  # N: class __main__.C is deprecated: use C2 instead
+x6: List[C]  # N: class __main__.C is deprecated: use C2 instead
+x7: List[List[C]]  # N: class __main__.C is deprecated: use C2 instead
+x8: List[Optional[Tuple[Union[List[C], int]]]]  # N: class __main__.C is deprecated: use C2 instead
+x9: Callable[[int], C]  # N: class __main__.C is deprecated: use C2 instead
+x10: Callable[[int, C, int], int]  # N: class __main__.C is deprecated: use C2 instead
+
+T = TypeVar("T")
+A1: TypeAlias = Optional[C]  # ToDo
+x11: A1
+A2: TypeAlias = List[Union[A2, C]]  # ToDo
+x12: A2
+A3: TypeAlias = List[Optional[T]]
+x13: A3[C]  # N: class __main__.C is deprecated: use C2 instead
+
 [builtins fixtures/tuple.pyi]