PnP dependencies priority

[justsaul]

It appears that peerDependencies have higher priority over regular dependencies when consuming packages.

Meaning if we have such set-up:

// test-app package.json
{
  "name": "test-app",
  "private": true,
  "dependencies": {
    "test-package": "20.0.0",
    "react": "17.0.0-rc.3"
  }
}

// test-package package.json
{
  "name": "test-package",
  "version": "20.0.0",
  "private": true,
  "dependencies": {
    "react": "18.2.0"
  },
  "peerDependencies": {
    "react": "*"
  },
}

when test-package functionality will be used within test-app, test-package will use react that comes from test-app (17.0.0-rc.3) instead of using it's internal react version that comes from its dependencies (18.2.0).

This behaviour makes total sense, however, since I couldn't find any documentation around this, I wanted to ask if it's intended and stable behaviour?

[merceyz]

Yes, it's documented here https://yarnpkg.com/configuration/manifest#peerDependencies

Note that peer dependencies can also be listed as regular dependencies; in this case, Yarn will use the package provided by the ancestors if possible, but will fallback to the regular dependencies otherwise