diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py index 549026ca89c25..76ed3892cfee2 100644 --- a/mypy/checkexpr.py +++ b/mypy/checkexpr.py @@ -3790,6 +3790,18 @@ def dangerous_comparison( if isinstance(left.value, bool) and isinstance(right.value, bool): # Comparing different booleans is not dangerous. return False + if isinstance(left, LiteralType) and isinstance(right, Instance): + # bytes/bytearray comparisons are supported + if left.fallback.type.fullname == "builtins.bytes" and right.type.has_base( + "builtins.bytearray" + ): + return False + if isinstance(right, LiteralType) and isinstance(left, Instance): + # bytes/bytearray comparisons are supported + if right.fallback.type.fullname == "builtins.bytes" and left.type.has_base( + "builtins.bytearray" + ): + return False return not is_overlapping_types(left, right, ignore_promotions=False) def check_method_call_by_name( diff --git a/test-data/unit/check-flags.test b/test-data/unit/check-flags.test index c6419923ebc62..c3a5f9e3bc045 100644 --- a/test-data/unit/check-flags.test +++ b/test-data/unit/check-flags.test @@ -2345,10 +2345,19 @@ x: int = "" # E: Incompatible types in assignment (expression has type "str", v x: int = "" # E: Incompatible types in assignment (expression has type "str", variable has type "int") [case testDisableBytearrayPromotion] -# flags: --disable-bytearray-promotion +# flags: --disable-bytearray-promotion --strict-equality def f(x: bytes) -> None: ... f(bytearray(b"asdf")) # E: Argument 1 to "f" has incompatible type "bytearray"; expected "bytes" f(memoryview(b"asdf")) +ba = bytearray(b"") +if ba == b"": + f(ba) # E: Argument 1 to "f" has incompatible type "bytearray"; expected "bytes" +if b"" == ba: + f(ba) # E: Argument 1 to "f" has incompatible type "bytearray"; expected "bytes" +if ba == bytes(): + f(ba) # E: Argument 1 to "f" has incompatible type "bytearray"; expected "bytes" +if bytes() == ba: + f(ba) # E: Argument 1 to "f" has incompatible type "bytearray"; expected "bytes" [builtins fixtures/primitives.pyi] [case testDisableMemoryviewPromotion]