When using a workspace, the transitive peerDependency of a package dependency is installed in the workspace's node_modules instead of being hoisted with the package

STR:

git clone https://github.com/julienw/vitest-types-issue
npm ci
cd packages/frontend
npx tsc

=> Typescript outputs errors because it can't find the right dependencies.

The repository has a single workspace in packages/frontend. There's no dependency defined at the workspace root.

This workspace contains these dependencies:

  "devDependencies": {
    "@vitest/browser-playwright": "4.1.5",
    "typescript": "6.0.3",
    "vitest": "4.1.5"
  }

@vitest/browser-playwright is also an optional peerDependency of vitest, with the same version.

When installing with npm ci (or npm i), we get this layout (I removed the unrelated packages from the output):

in /node_modules:

playwright/
playwright-core/
typescript/
vite/
'@vitest'/
- browser/
- expect/
- mocker/
- pretty-format/
- runner/
- snapshot/
- spy/
- utils/
vitest/

in /packages/frontend/node_modules:

@vitest/browser-playwright/

There's an error because vitest/browser (/!\ it's not @vitest/browser) exports types from @vitest/browser-playwright, but because @vitest/browser-playwright is in the workspace, typescript doesn't find it.

I think it's a bug in npm because:

• @vitest/browser-playwright is a peerDependency of vitest so it should be installed along it
• even dependencies of @vitest/browser-playwright are hoisted to the root (eg: the dependency @vitest/browser or the non-optional peer dependency playwright).

What do you folks think?

Use the linked reproduction repository: run npm ci, change to packages/frontend, and run npx tsc to confirm the missing type resolution. Inspect npm's workspace dependency installation and hoisting behavior around the reported node_modules layouts; done means the transitive peer dependency is installed with the package at the root and npx tsc completes without these errors.