Object.defineProperty(Array.prototype .. problem in TypeScript

Question

In some old QA, I found a couple of code such as

I am investigating how it behaves under TypeScript.

interface Array<T> {
  "foo": Function;
  ["foo"]: Function;
}

Object.defineProperty(Array.prototype, "foo", {
  value: function <T>(this, R: T) {
    return (console.log(R));
  }
});

[].foo("test");   // test
[]["foo"]("test");  //test

Basically, the code works, The TypeScript Playground

However, for some reason, in VSCode, TypeScript produces errors

At least I tried to type the Array property.

"suppressImplicitAnyIndexErrors": true in tsconfig.json surely suppresses these errors, but I want to know how to make it work without this flag.

Any idea? Thanks.

Please share any relevant code by editing your Question - instead of a screenshot. Fewer people are likely to reproduce your issue without having your code in a copyable form. — Algamest
– Algamest, Commented Oct 25, 2021 at 14:38
Please provide a minimal reproducible example that clearly demonstrates the issue you are facing. Ideally someone could drop the code into a standalone IDE like The TypeScript Playground (link here!) and immediately get to work solving the problem without first needing to re-create it. Right now there are no errors in the TS Playground, so your issue isn't clear. I suspect it has to do with modules and you will need to do some global augmentation to deal with it, but without a minimal reproducible example it's just speculation. — jcalz
– jcalz, Commented Oct 25, 2021 at 14:48
@jcalz Thanks for your playground link, and I added in my Question. I feel somewhat better it works without problem there. I don't know why my VScode environment produces the errors. — Functor
– Functor, Commented Oct 25, 2021 at 15:08
I think at this point, assuming you want to figure this out, your job is now to reproduce the issue yourself in a different environment, such as the TS Playground. Copy more of your code into the other IDE and see what happens (hint: do you have any code with export in it?) and work on it until you get a minimal reproducible example. Good luck! — jcalz
– jcalz, Commented Oct 25, 2021 at 15:12

Functor · Accepted Answer · 2021-10-25 15:21:09Z

0

Thanks a lot for your inspirations especially for @jcalz.

Here's the thing...

interface Array<T> {
  "foo": Function;
  ["foo"]: Function;
}

must be the top level of the code of TypeScript, that I really did not know.

Thank you guys anyway!!

answered Oct 25, 2021 at 15:21

Functor

6104 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Object.defineProperty(Array.prototype .. problem in TypeScript

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related