instanceof + extended native class

[GordonSmith]

TypeScript Version: 2.1.4

class MyC extends Error {
    constructor(msg: string) {
        super(msg);
    }
}

let myC = new MyC("Hmmm");
let test3 = myC instanceof Error;   //TRUE
let test4 = myC instanceof MyC;     //!!!FALSE!!!

Expected behavior: test4 should be TRUE

Actual behavior: test4 is FALSE

[alitaheri]

Test nightly too. It might be fixed there.

[gcnew]

Unless you know the nits and grits of JavaScript, don't extend natives, it does't work (FAQ).

BTW: what keywords did you use to search for existing issues? This question gets asked every other day, so it seems the TS team might have to boost its discoverability, although a simple search gives plenty of good results.

[GordonSmith]

That FAQ is out of date and that specific section is no longer valid since 1.6 - I did make it as far as: #1168 - still my bad for not spotting this is a duplicate and I will close.

[gcnew]

Actually that specific section is fairly new. According to the history log (see rev 5c207fc) it is 25 days old as of today. As such it is the most recent and preferred approach.