Type checking is too slow

[keithamus]

Type checking is too slow

[iansan5653]

As another data point, I see similarly long times in Codespaces:

$ time (npm run type-check -w @primer/react >> dev/null)

real    0m22.054s
user    0m34.194s
sys     0m1.221s

That said, I haven't noticed issues with the VSCode extension; incremental checking in that form seems to work pretty quickly.

We are talking about over 85k lines of TypeScript -- I'd be interested in knowing what 'typical' tsc performance looks like to see if/how bad our code really is, vs just the typechecker not being that fast in general. (Although even if we're seeing typical times, there's still no reason not to try and get some performance gains if it's not too much effort and doesn't require sacrificing code quality)

[siddharthkp]

That's surprisingly long! Do you get instant feedback in your editor or do you have to wait more than 1-2 seconds for that as well?

[joshblack]

Definitely all for improving performance 👍 Would be great to know what's the floor performance-wise for a project this size along with what the effort would be to get there 👀 When it comes to simplifying types, another possible benefit for this could be improved docgen on the storybook side if they're easier to infer which would be great.

Random, is it possible to profile the project and see which files or types are contributing the most to the check phase?