v/vlib/v/checker/tests/no_method_on_interface_propagation.vv

struct Cat {
	breed string
}

interface Animal {
	breed string
}

fn (a Animal) foo() {}

fn new_animal(breed string) Animal {
	return &Cat{breed}
}

fn test_methods_on_interfaces_dont_exist_on_implementers() {
	a := new_animal('persian')
	if a is Cat {
		a.foo()
	}
}