Support using the target + lib options to resolve d.ts per playground session

[orta]

I was trying to help someone with a problem using Object.entries but the playground didn't think it existed. The options panel is great, but doesn't offer a way to specify the lib option. This is a fairly troublesome issue when trying to help people with their modern, up-to-date code.

Perhaps a short-term easy fix would be to default to the latest libs?

Eventually, being able to specify libs (or even a full tsconfig.json as suggested in #4) would probably be best.

[orta]

I've added the extra paragraph from your original post 👍

[orta]

This got update to ES2015 - so for now I'll close it

[orta]

I've been using this as the catch-all for grabbing the right lib files for the TS Playground - so we'll keep it here

[apieceofbart]

What about stuff like Array.prototype.includes ?

[orta]

That's what this issue is about - I shipped a deploy change which makes the nightly builds use the ESNext build last week, so you can test out what it will be like for 4.0 here: https://www.staging-typescript.org/play?ts=next

[apieceofbart]

@orta wow, this looks awesome! thanks a lot!