Bring back const enums

[taralx]

History: #295

So there was a transpilation bug (microsoft/TypeScript#40499) that some people ran into, but that was fixed in Typescript 4.2. It should be possible to set preserveConstEnums and get the best of both worlds. I wouldn't be so bothered except my bundle size (via parcel) goes from 3k to 27k because it pulls in the whole big chunk for just a few numbers.

[IRONM00N]

Even with preserveConstEnums enabled, ts doesn't allow reverse mapping for const enums.

[taralx]

It doesn't? https://www.typescriptlang.org/play?preserveConstEnums=true#code/MYewdgzgLgBApmArgWxgCTgG0yGBvAKBmJgEEYBeGARgIF8Cg

[vladfrangu]

const enums have been very much a pain point in the library (and in the TypeScript ecosystem as a whole).

Read more: microsoft/TypeScript#30590

As such, we will not bring them back. I'd be more worried why parcel or whatever bundler you use doesn't treeshake properly (is this our fault? Is it something else?)

Feel free to open an issue (or even a pull request) if treeshaking fails, and a repository to test it with, and we'll take a look :D

[taralx]

That's fair. Thank you for the detailed response.