Why does 1 + "foo" type check? #52

6862bbd
2021-10-14

What program did you run?

def f():
    return 1 + "foo"

f()

What happened?

The program passes type checks.

What should have happened?

We expected a compile-time error complaining that we can't add up int and str.

BTW, the type of int's __add__ method is printed in an interesting way, what does that type mean?

reveal_type((42).__add__)
# compiler.static.errors.TypedSyntaxError:
# reveal_type(int(42).__add__):
# 'int.__add__'