Resolve GenericType nodes better in LookupLocalTypes.

For python/typeshed#7680.

PiperOrigin-RevId: 447596238

Author: rchen152

pytype/load_pytd_test.py

@@ -600,6 +600,18 @@ def test_bad_parameterization(self):
         Strings = a.Alias[str, str]
       """)
 
+  def test_parameterize_twice(self):
+    ast = self._import(a="""
+      from typing import AnyStr, Generic
+      class Foo(Generic[AnyStr]): ...
+    """, b="""
+      import a
+      from typing import AnyStr
+      x: Foo[str]
+      Foo = a.Foo[AnyStr]
+    """)
+    self.assertEqual(pytd_utils.Print(ast.Lookup("b.x").type), "a.Foo[str]")
+
 
 _Module = collections.namedtuple("_", ["module_name", "file_name"])
 

pytype/pytd/visitors.py

@@ -329,6 +329,18 @@ def MaybeSubstituteParameters(base_type, parameters=None):
   return base_type.Visit(ReplaceTypeParameters(mapping))
 
 
+def _MaybeSubstituteParametersInGenericType(node):
+  if isinstance(node.base_type, (pytd.GenericType, pytd.UnionType)):
+    try:
+      node = MaybeSubstituteParameters(
+          node.base_type, node.parameters) or node
+    except ValueError as e:
+      raise KeyError(str(e)) from e
+  elif isinstance(node.base_type, pytd.AnythingType):
+    return node.base_type
+  return node
+
+
 class LookupExternalTypes(_RemoveTypeParametersFromGenericAny, _ToTypeVisitor):
   """Look up NamedType pointers using a symbol table."""
 
@@ -482,13 +494,7 @@ def VisitClassType(self, t):
       return new_type
 
   def VisitGenericType(self, node):
-    if isinstance(node.base_type, (pytd.GenericType, pytd.UnionType)):
-      try:
-        node = MaybeSubstituteParameters(
-            node.base_type, node.parameters) or node
-      except ValueError as e:
-        raise KeyError(str(e)) from e
-    return node
+    return _MaybeSubstituteParametersInGenericType(node)
 
   def _ModulePrefix(self):
     return self.name + "." if self.name else ""
@@ -757,6 +763,9 @@ def VisitClassType(self, t):
         t.cls = cast(pytd.ClassType, self.VisitNamedType(lookup_type)).cls
     return t
 
+  def VisitGenericType(self, node):
+    return _MaybeSubstituteParametersInGenericType(node)
+
 
 class ReplaceTypes(Visitor):
   """Visitor for replacing types in a tree.