Add a method to builtin String type

[Clark McCauley]

I'd like to add a method to the built-in string type. Here's what I've got, and the error I am getting. First of all, is what I'm doing possible, and if so, what am I doing wrong?

runtime.Get("String").ToObject(runtime).Set("toElement", func(call goja.FunctionCall) goja.Value {
    return nil
})

"foobar".toElement()

Object has no member 'toElement' at <eval>:1:26(2)

[Dmitry Panov]

You need to define the method on String.prototype, not on String.

[Clark McCauley]

@dop251 ah, thank you. I tried this and am still getting the same error, so I'm assuming I'm doing something wrong...

runtime.Get("String").ToObject(runtime).Prototype().Set("toElement", func(call goja.FunctionCall) goja.Value {
    return nil
})

[Dmitry Panov]

Yes, what you're doing is String.__proto__.toElement = ..., and you need String.prototype.toElement = ..., i.e.

runtime.Get("String").ToObject(runtime).Get("prototype").ToObject(runtime).Set("toElement", func(call goja.FunctionCall) goja.Value {
    return nil
})

[Clark McCauley]

Worked perfectly. Thanks!