TypeScript type checker

[kdy1]

Closing as the stc is now abandoned. TypeScript was not something that I could follow up on in an alternative language.

[dsherret]

I'm just looking at this: https://github.com/kdy1/swc/tree/e88e5e4c824926e5f3a5240986c33bb30f7508b5/typescript/checker

Won't re-writing the TS type checker in rust be a lot of work? There's so many edge cases! Why not just do what babel does and tell people to run the typescript type checker over the code with emitting? Alternatively, you could build something into the swc JS package that uses the typescript compiler api to do this as well.

[dsherret]

What might be neat is something that converts swc AST nodes to TypeScript compiler api nodes. So you could parse the nodes with swc, send them over to JS, convert them to typescript compiler api nodes, then it could do the type checking using those nodes.

[kdy1]

@dsherret I'm porting tsc because it is wall-clock grade slow.

[dsherret]

True, it could be faster, but there's a whole team of developers working on TypeScript daily. It will be very hard to get all the edge cases, but perhaps you could repurpose the tests the typescript team uses in the typescript repo.

Anyway, you have a long and continually expanding road ahead of you :)

[kdy1]

I'm already using tests from typescript repository :)
I know that it's a very hard task, but it's fun for me.

[dsherret]

That’s awesome. Well, you’ve done an excellent job with the library and you’re very fast at programming so good luck! 😀

[IronSean]

The other approach you can use with babel is do just do compilation, and run the type checker without emitting in a separate thread so even if it's slower, your build still finishes fast. That might currently work with swc? But the idea of a much faster type checker is also very exciting!

[kyegupov]

@kdy1 what's the current status? What's the most up-to-date branch in your fork? I have a feeling you won't be able to pull this alone. Maybe we can create a plan to "move Mount Fuji" and get more people involved?

[nayeemrmn]

https://deno.land/v1#tsc-bottleneck