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I'm very impressed with the collaboration we've seen from TypeScript to make Node integration a success. It is a team effort with all participants leaning in. Extension rewriting in TS 5.7 is the first treat. This was directly motivated by the Node use-case. And there's more to come! 💙

Honestly the only change to TS that has made me cringe and think through the use-cases. I'm *very* torn to put it safely.

This is a move that makes it feel like TS is it's own language when it reality it's a superset of JS designed as a superset to work with types stripped off the syntax. Imports are no longer required to be valid for the environment you are authoring.

If this is the direction it's taking, either knowingly or accidentally, another TS / Flow will emerge. I don't want it to, but watch it happen.

I get it. The rewriting is a semi-complex runtime transform with a runtime helper. One motive is to promote npm packages publishing *.d.ts files. Another is to facilitate maintaining *.js as the executable format for publishing. @searyanc.dev did not merge it accidentally.

I'll have to search through the issues and read through the thought process that lead to the change in opinion from the team.

In short, Node.js started being able to execute TypeScript directly, and we did not want to leave users in a postion where they couldn't publish their TypeScript code without converting all of their code back to JS extension imports that may or may not be exectuable as TS.

To be clear, the positon has always been "TypeScript describes code that can be executed". Node couldn't run TS or with TS extensions, so, we didn't rewrite anything. Now it can, so it should work. May as well make it work well.

A flag which bans TS features with runtime emit (enums, namespaces, experimental decorators, etc) will come in 5.8 to help people executing TS code via Node.js (or who want to avoid using those features for "reasons").

I like that this flag is comming! Kind of like strict typescript It will also mean having a flag to disable ts enums and that's a win too

I mostly don't like TS enums because TS string unions are just better (no import, and 99% of the time, the enum name is redundant in usage) and more like JS work: structural vs nominal

That's fair, though I think that enums being numbers is good for perf, bit flag enums are pretty useful, and reverse mapping is too. Sort of hard to replace those...

Yeah in the TS compiler they are used for good reasons. For most codebases that also used experimental decorators it was used for the bad reason: expecting TS to be written like Java or C#