[bigjoemuffaraw]

In projects where the node_modules folder starts to get out of hand, I set `"skipLibCheck": true,` in the compilerOptions of my tsconfig file (at least for dev builds).

In my understanding, it skips type-checking any d.ts files (which most packages include by now) which dramatically lowers compile time. In the authors case it looks like their project is about 400kb of their own code and then 30mb of node_modules libraries.

I think it also skips your own d.ts files (it isn't limited to node_modules), so this might just be a way to dramatically speed up your footgun. I have literally never written my own d.ts file though so it works for my purposes

[danvk]

My understanding is that skipLibCheck skips _type checking_ .d.ts files, i.e. looking for type errors in them. But tsc still has to read those files since you might refer to their types in your own code, which TypeScript will type check.

[geraldwhen]

That’s not how that works. All imported type files are checked. Skip lib check skips checking types that aren’t imported.