diff --git a/mypy/semanal_namedtuple.py b/mypy/semanal_namedtuple.py index 37a650f1b664..f27c89e34fdf 100644 --- a/mypy/semanal_namedtuple.py +++ b/mypy/semanal_namedtuple.py @@ -34,6 +34,7 @@ NamedTupleExpr, NameExpr, PassStmt, + PlaceholderNode, RefExpr, Statement, StrExpr, @@ -697,10 +698,14 @@ def save_namedtuple_body(self, named_tuple_info: TypeInfo) -> Iterator[None]: if isinstance(sym.node, (FuncBase, Decorator)) and not sym.plugin_generated: # Keep user-defined methods as is. continue - # Keep existing (user-provided) definitions under mangled names, so they - # get semantically analyzed. - r_key = get_unique_redefinition_name(key, named_tuple_info.names) - named_tuple_info.names[r_key] = sym + # Do not retain placeholders - we'll get back here if they cease to + # be placeholders later. If we keep placeholders alive, they may never + # be reached again, making it to cacheable symtable. + if not isinstance(sym.node, PlaceholderNode): + # Keep existing (user-provided) definitions under mangled names, so they + # get semantically analyzed. + r_key = get_unique_redefinition_name(key, named_tuple_info.names) + named_tuple_info.names[r_key] = sym named_tuple_info.names[key] = value # Helpers diff --git a/test-data/unit/check-namedtuple.test b/test-data/unit/check-namedtuple.test index 45de2a9e50ae..66eb555421f4 100644 --- a/test-data/unit/check-namedtuple.test +++ b/test-data/unit/check-namedtuple.test @@ -1530,3 +1530,28 @@ class Base: names = [name for name in namespace if fail] # E: Name "fail" is not defined self.n = namedtuple("n", names) # E: NamedTuple type as an attribute is not supported [builtins fixtures/tuple.pyi] + +[case testNamedTupleDefaultValueDefer] +# flags: --debug-serialize +from typing import NamedTuple + +class NT(NamedTuple): + foo: int = UNDEFINED # E: Name "UNDEFINED" is not defined +[builtins fixtures/tuple.pyi] + +[case testNamedTupleDefaultValueDefer2] +# flags: --debug-serialize +from typing import NamedTuple + +class NT(NamedTuple): + foo: int = DEFERRED_INT + +class NT2(NamedTuple): + foo: int = DEFERRED_STR # E: Incompatible types in assignment (expression has type "str", variable has type "int") + +from foo import DEFERRED_INT, DEFERRED_STR + +[file foo.py] +DEFERRED_INT = 1 +DEFERRED_STR = "a" +[builtins fixtures/tuple.pyi]