From 5c7fe481c38f47c507c1ba34046491a9ad1cad35 Mon Sep 17 00:00:00 2001 From: Jannic Warken Date: Tue, 14 May 2024 16:40:24 +0200 Subject: [PATCH] Revert changes and only keep removal of type erase --- mypy/subtypes.py | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/mypy/subtypes.py b/mypy/subtypes.py index 51b09432499d..81132e089b89 100644 --- a/mypy/subtypes.py +++ b/mypy/subtypes.py @@ -1917,7 +1917,8 @@ def restrict_subtype_away(t: Type, s: Type) -> Type: ideal result (just t is a valid result). This is used for type inference of runtime type checks such as - isinstance(). Currently, this just removes elements of a union type. + isinstance() or TypeIs. Currently, this just removes elements + of a union type. """ p_t = get_proper_type(t) if isinstance(p_t, UnionType): @@ -1926,24 +1927,21 @@ def restrict_subtype_away(t: Type, s: Type) -> Type: new_items = [ restrict_subtype_away(item, s) for item in p_t.relevant_items() - if not covers_at_runtime(item, s) + if (isinstance(get_proper_type(item), AnyType) or not covers_type(item, s)) ] return UnionType.make_union(new_items) - elif covers_at_runtime(t, s): + elif covers_type(t, s): return UninhabitedType() else: return t -def covers_at_runtime(item: Type, supertype: Type) -> bool: - """Will isinstance(item, supertype) always return True at runtime?""" +def covers_type(item: Type, supertype: Type) -> bool: + """Returns if item is covered by supertype.""" item = get_proper_type(item) supertype = get_proper_type(supertype) - if isinstance(item, AnyType): - return False - - if is_subtype(item, supertype, ignore_promotions=True): + if is_proper_subtype(item, supertype, ignore_promotions=True, erase_instances=True): return True if isinstance(supertype, Instance): if supertype.type.is_protocol: