foo == nil Checks in Go for InterfacesYou can simply never trust something like the following, ever, to do the right thing:
func Some(foo FooInterface) {
if foo != nil {
fmt.Println("always true")
}
}
This condition will always be true because the comparison to nil is
fucking brain-dead in Go. Both the type and the value have to match, and
they don’t usually when working with interfaces in any way.
The only realistic option is to use lame-ass reflection:
func Some(foo FooInterface) {
if !reflect.ValueOf(foo).IsNil() {
fmt.Println("always true")
}
}
This is such a huge, stupid issue, that I’ve created a check.Nil() check
in bonzai to help me (and others) avoid this.