Remove type aliases that are long supported (#16039)

sobolevn · pre-commit-ci[bot] · web-flow · commit bd212bcc2229 · 2023-09-04T18:43:05.000+03:00
Some builtin aliases are available for all python versions that we support. So, there's no need to check them in `semanal`: https://github.com/python/mypy/blob/8738886861682e0d168ea321c2cc6ee5b566cb8b/mypy/semanal.py#L673-L689 --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
diff --git a/mypy/nodes.py b/mypy/nodes.py
@@ -138,18 +138,7 @@ def set_line(
 
 # This keeps track of the oldest supported Python version where the corresponding
 # alias source is available.
-type_aliases_source_versions: Final = {
-    "typing.List": (2, 7),
-    "typing.Dict": (2, 7),
-    "typing.Set": (2, 7),
-    "typing.FrozenSet": (2, 7),
-    "typing.ChainMap": (3, 3),
-    "typing.Counter": (2, 7),
-    "typing.DefaultDict": (2, 7),
-    "typing.Deque": (2, 7),
-    "typing.OrderedDict": (3, 7),
-    "typing.LiteralString": (3, 11),
-}
+type_aliases_source_versions: Final = {"typing.LiteralString": (3, 11)}
 
 # This keeps track of aliases in `typing_extensions`, which we treat specially.
 typing_extensions_aliases: Final = {
diff --git a/mypy/semanal.py b/mypy/semanal.py
@@ -680,7 +680,10 @@ def add_builtin_aliases(self, tree: MypyFile) -> None:
         """
         assert tree.fullname == "typing"
         for alias, target_name in type_aliases.items():
-            if type_aliases_source_versions[alias] > self.options.python_version:
+            if (
+                alias in type_aliases_source_versions
+                and type_aliases_source_versions[alias] > self.options.python_version
+            ):
                 # This alias is not available on this Python version.
                 continue
             name = alias.split(".")[-1]
