imp = import "import"

func() =
    __file__ = "foo"
    __file__

C = Class()
C.
    __file__ = "bar"

assert __file__.endswith "dunder.er"
assert func() == "foo"
assert module::__file__.endswith "dunder.er"
assert C.new().__file__ == "bar"
assert imp.func().endswith "import.er"

discard Str()
discard Str(1)
discard Str(bytes("aaa", "utf-8"), "utf-8")