On: What’s New in ES2019

[vimslayer]

In the current proposal,

    case (value) {
        when { constructor: Buffer } ->
            console.log("It's a Buffer!")
    }

that doesn't handle subtying though and doesn't work across realms.

[SomeOldThrow → vimslayer]

Oh interesting you can match on that!

However I think my point stands that javascript has runtime conceptions of types that go beyond duck typing.