TypeScript plugin + Transformers

[danfma-daitan]

Hello everyone!

I know that transformers are not a big thing yet in the TypeScript world, but they can be very helpful in some cases.
So, is there a way to update the typescript-plugin to use the ttypescript as an option, so we could use some typescript transformers? (eg. https://github.com/danfma/mobx-activator).

For what I remember, this package is compatible with the latest TypeScript version, so if I was possible to use a "chosen" TypeScript implementation, then I would be able to replace the "typescript" with the "ttypescript" and use the transformers in my tsconfig.json directly.

https://github.com/cevek/ttypescript

[rossng]

This would also be very useful for me. If there was just a plugin option that allowed swapping out tsc for ttsc (or any other command) here, that would probably do it.

[EdNutting]

I have created a PR to add support for using ttsc for type checking: #2131

No idea how to make this work for the main build because everything is built around esbuild.

[FredKSchott]

That's my only question about your PR: we'll keep using esbuild as the main "build" step for TypeScript (basically just strips types to create JS) and this plugin will continue to do the "type check" step. I'm not familiar with ttsc, but is that still useful as just a type checker?

Just want to confirm that ttsc doesn't assume file build control before merging this support.

[EdNutting]

It's useful if you want to be able to extend the typechecker, but it won't help with the build side of things - as you have noted. (Using transformers in the build was what Ross and I were intending to solve but esbuild is a complete roadblock to that.)

So my PR is a first step towards more flexible TypeScript support, but certainly doesn't close this discussion.

[FredKSchott]

Sounds good, thanks for clarifying.

You can check out the Babel plugin to see what it would look like to have TypeScript take over the build as well. Unfortunately, Snowpack's single-file build system may not align with TypeScript's "build the entire project at once" approach. But, could be worth a try to explore!