Warn deprecated constructor calls from old-style type aliases

Author: bzoracler

mypy/checkexpr.py

@@ -1679,6 +1679,12 @@ def check_callable_call(
             callable_info: TypeInfo | None = None
             if isinstance(callable_node.node, TypeInfo):
                 callable_info = callable_node.node
+            elif (
+                isinstance(callable_node.node, TypeAlias)
+                and isinstance(callable_node.node.target, Instance)
+                and isinstance(callable_node.node.target.type, TypeInfo)
+            ):
+                callable_info = callable_node.node.target.type
             if callable_info is not None:
                 self.chk.check_deprecated(callee.definition, context)
 

test-data/unit/check-deprecated.test

@@ -370,6 +370,35 @@ class D(C):
 [builtins fixtures/tuple.pyi]
 
 
+[case testDeprecatedClassConstructorCalledFromTypeAlias]
+# flags: --enable-error-code=deprecated
+
+from typing_extensions import deprecated, TypeAlias
+
+class A:
+    @deprecated("do not use")
+    def __init__(self) -> None: ...
+
+class B(A): ...
+
+A_alias = A
+A_explicit_alias: TypeAlias = A
+B_alias = B
+B_explicit_alias: TypeAlias = B
+
+A_alias()  # E: function __main__.A.__init__ is deprecated: do not use
+A_explicit_alias()  # E: function __main__.A.__init__ is deprecated: do not use
+B_alias()  # E: function __main__.A.__init__ is deprecated: do not use
+B_explicit_alias()  # E: function __main__.A.__init__ is deprecated: do not use
+
+A_alias
+A_explicit_alias
+B_alias
+B_explicit_alias
+
+[builtins fixtures/tuple.pyi]
+
+
 [case testDeprecatedSpecialMethods]
 # flags: --enable-error-code=deprecated