peer deps resolution

[mzleman]

My pnpm version is 10, and my project folder structure as follows:

--pnpm-workspace.yaml

packages:
   packages/*'

--package.json

{
   "devDependencies": {
      "bun-types": "latest"   // it takes @types/react@^19 as a peer dep
   }
}

--packages
----a
------package.json
{ devDependencies: { "@types/react": ^18 } }

⭐Result：after run pnpm install, only @types/react^18 installed, no @types/react^19 in the .pnpm folder.

Then, i tried two different cases

case 1

--package.json
{ "devDependencies": { "bun-types": "latest" // it takes @types/react@^19 as a peer dep } }

--packages
----a
------package.json
{ devDependencies: { "@types/react": ^18 } }
----b
------package.json
{ devDependencies: { "@types/react": ^19 } }
⭐Result: both @types/react^18 and @types/react@^19 are in the .pnpm folder

case 2

--package.json
{ "devDependencies": { "bun-types": "latest" // it takes @types/react@^19 as a peer dep } }

--packages
----a
------ package.json
{ devDependencies: { // nothing } }

⭐Result: @types/react@^19 is auto installed (as a peer dep) in the .pnpm folder

🙏 Could anyone help me understand the resolution strategy?

It seems that if some workspace explicitly declares @types/react as a dep or dev dep, the root workspace won't auto install a peer dep to meet the sermantic version request.