[robpalmer]

I would never say never for any potential ECMAScript feature. Each time people say "JS will never do x", a few years later it does. Brendan Eich has a slide on this.

https://www.slideshare.net/BrendanEich/jslol-9539395/110-Alw...

In terms of whether JS will introduce things that conflict with TS, it's hard to say. TypeScript team themselves are active participants in TC39, championing recent features such as Optional Chaining and Nullish Coalescing. So if there were any conflicts, or even opportunities for confusion, it would all be managed way ahead of time. Several TC39 delegates are users of TypeScript so there is no risk of accidents here (in my opinion).

[Chris_Newton]

I would never say never for any potential ECMAScript feature.

Sure, and again, at the scale in your organisation, taking an absolute position on this makes a lot of sense and I can respect the principled stance.

On the other hand, the trade-off in this case is giving up a tool that is widely useful immediately in exchange for a potential/hypothetical benefit later. For other development teams, perhaps those alternatives would be weighted differently. And then that in turn might affect how any future changes were viewed by the relevant language committees, who as you say would surely be aware of the implications.

Anyway, thanks for sharing your insights, both here and in the original article. It’s somehow reassuring to me that I’m not the only person in the world who wants their front-end code to continue working for more than five minutes, when it seems like a lot of the front-end community would consider that a pretty good working lifetime for code these days!

[robpalmer]

That's a very real trade-off and something we have to carefully make a judgement call on every time. In this specific case the decision is made a lot easier due to the fact that string unions are often a simpler alternative.

  type Color = "red" | "green" | "blue";

Glad to hear you appreciated the article!