Destruction of TypeScript ecosystem on npm is expanding

[falsandtru]

As I mentioned at #31148, unused @types files installed by node modules pollutes and breaks the main project. It is caused by del package at that time. Now this problem came to be spread by another major package npm-check-updates. This means the destruction of ecosystem is expanding. TypeScript must resolve the problem quickly. See a solution #18588 (comment).

[falsandtru]

My proposal is #18588 (comment). You just implement it.

[ExE-Boss]

I believe that the best option is to just use pnpm, which doesn’t have this problem, as packages are stored in isolated trees and are symlinked to each other.

---

pnpm file hierarchy for del@4.1.1:
(only relevant @types packages are included)

node_modules/
- del - .registry.npm.com/del/4.1.1/node_modules/del
- .registry.npmjs.com/
	- @types/
		- glob/
			- <version>/
				- node_modules/
					- @types/
						- glob/
						- node - ../../../../../@types/node/<version>/node_modules/@types/node
		- node/
	- del/
		- 4.1.1/
			- node_modules/
				- del/
				- @types/
					- glob - ../../../../../@types/glob/<version>/node_modules/@types/glob

TypeScript only looks into node_modules/@types/, not into node_modules/.registry.npmjs.com/@types/<package>/<version>/node_modules/@types/

[StreetStrider]

@ExE-Boss, hello. I came to this ticket by the opposite reason. I'm already using pnpm actively in my non-TS projects. However, when I try to install @types package in pnpm (with classic deps tree hierarchy) tsc rejects to resolve transient dependencies of such @types packages. Just to check my guess, I tried reinstalling with vanilla npm (flat deps). From that point tsc works OK, which means no errors in my typed code. However when I switch back with pnpm install tsc starts to nag again, like:

node_modules/@types/express/index.d.ts:19:23 - error TS2307: Cannot find module 'express-serve-static-core'.

19 import * as core from "express-serve-static-core";

(I depend on @types/express).
Have you faced similar issues (in past or present)? Is it my own issue which I should investigate further or tsc now hard depends on flat order of dependecies?

[StreetStrider]

Looks like my issue is #30858, but not sure.