fix: warn when linking a package with peerDeps (#6956)

close #615

.changeset/empty-teachers-fry.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/plugin-commands-installation": patch
+"pnpm": patch
+---
+
+Warn when linking a package with peerDependencies [615](https://github.com/pnpm/pnpm/issues/615).

pkg-manager/plugin-commands-installation/src/link.ts

@@ -21,6 +21,7 @@ import {
   type LinkFunctionOptions,
   type WorkspacePackages,
 } from '@pnpm/core'
+import { logger } from '@pnpm/logger'
 import pLimit from 'p-limit'
 import pathAbsolute from 'path-absolute'
 import pick from 'ramda/src/pick'
@@ -35,6 +36,17 @@ const isWindows = process.platform === 'win32' || global['FAKE_WINDOWS']
 const isFilespec = isWindows ? /^(?:[.]|~[/]|[/\\]|[a-zA-Z]:)/ : /^(?:[.]|~[/]|[/]|[a-zA-Z]:)/
 const installLimit = pLimit(4)
 
+type LinkOpts = CreateStoreControllerOptions & Pick<Config,
+| 'bin'
+| 'cliOptions'
+| 'engineStrict'
+| 'saveDev'
+| 'saveOptional'
+| 'saveProd'
+| 'workspaceDir'
+| 'sharedWorkspaceLockfile'
+> & Partial<Pick<Config, 'linkWorkspacePackages'>>
+
 export const rcOptionsTypes = cliOptionsTypes
 
 export function cliOptionsTypes () {
@@ -82,17 +94,29 @@ export function help () {
   })
 }
 
+async function checkPeerDeps (linkCwdDir: string, opts: LinkOpts) {
+  const { manifest } = await tryReadProjectManifest(linkCwdDir, opts)
+
+  if (manifest?.peerDependencies && Object.keys(manifest.peerDependencies).length > 0) {
+    const packageName = manifest.name ?? path.basename(linkCwdDir) // Assuming the name property exists in newManifest
+    const peerDeps = Object.entries(manifest.peerDependencies)
+      .map(([key, value]) => `  - ${key}@${value}`)
+      .join(', ')
+
+    logger.warn({
+      message: `The package ${packageName}, which you have just pnpm linked, has the following peerDependencies specified in its package.json:
+      
+${peerDeps}
+
+The linked in dependency will not resolve the peer dependencies from the target node_modules. 
+This might cause issues in your project. To resolve this, you may use the "file:" protocol to reference the local dependency.`,
+      prefix: opts.dir,
+    })
+  }
+}
+
 export async function handler (
-  opts: CreateStoreControllerOptions & Pick<Config,
-  | 'bin'
-  | 'cliOptions'
-  | 'engineStrict'
-  | 'saveDev'
-  | 'saveOptional'
-  | 'saveProd'
-  | 'workspaceDir'
-  | 'sharedWorkspaceLockfile'
-  > & Partial<Pick<Config, 'linkWorkspacePackages'>>,
+  opts: LinkOpts,
   params?: string[]
 ) {
   const cwd = process.cwd()
@@ -122,6 +146,9 @@ export async function handler (
     if (path.relative(linkOpts.dir, cwd) === '') {
       throw new PnpmError('LINK_BAD_PARAMS', 'You must provide a parameter')
     }
+
+    await checkPeerDeps(linkCwdDir, opts)
+
     const { manifest, writeProjectManifest } = await tryReadProjectManifest(opts.dir, opts)
     const newManifest = await addDependenciesToPackage(
       manifest ?? {},
@@ -185,6 +212,12 @@ export async function handler (
 
   const { manifest, writeProjectManifest } = await readProjectManifest(linkCwdDir, opts)
 
+  await Promise.all(
+    pkgPaths.map(async (dir) => {
+      await checkPeerDeps(dir, opts)
+    })
+  )
+
   const linkConfig = await getConfig(
     { ...opts.cliOptions, dir: cwd },
     {

pkg-manager/plugin-commands-installation/test/link.ts

@@ -5,6 +5,7 @@ import { install, link } from '@pnpm/plugin-commands-installation'
 import { prepare, preparePackages } from '@pnpm/prepare'
 import { assertProject, isExecutable } from '@pnpm/assert-project'
 import { fixtures } from '@pnpm/test-fixtures'
+import { logger } from '@pnpm/logger'
 import { sync as loadJsonFile } from 'load-json-file'
 import PATH from 'path-name'
 import writePkg from 'write-pkg'
@@ -276,3 +277,83 @@ test('link fails if nothing is linked', async () => {
     }, [])
   ).rejects.toThrow(/You must provide a parameter/)
 })
+
+test('logger warns about peer dependencies when linking', async () => {
+  prepare()
+
+  const warnMock = jest.spyOn(logger, 'warn')
+
+  process.chdir('..')
+  const globalDir = path.resolve('global')
+
+  await writePkg('linked-with-peer-deps', {
+    name: 'linked-with-peer-deps',
+    version: '1.0.0',
+    peerDependencies: {
+      'some-peer-dependency': '1.0.0',
+    },
+  })
+
+  process.chdir('linked-with-peer-deps')
+
+  const linkOpts = {
+    ...DEFAULT_OPTS,
+    bin: path.join(globalDir, 'bin'),
+    dir: globalDir,
+  }
+  await link.handler({
+    ...linkOpts,
+  })
+
+  process.chdir('..')
+  process.chdir('project')
+
+  await link.handler({
+    ...linkOpts,
+  }, ['linked-with-peer-deps'])
+
+  expect(warnMock).toHaveBeenCalledWith(expect.objectContaining({
+    message: expect.stringContaining('has the following peerDependencies specified in its package.json'),
+  }))
+
+  warnMock.mockRestore()
+})
+
+test('logger should not warn about peer dependencies when it is an empty object', async () => {
+  prepare()
+
+  const warnMock = jest.spyOn(logger, 'warn')
+
+  process.chdir('..')
+  const globalDir = path.resolve('global')
+
+  await writePkg('linked-with-empty-peer-deps', {
+    name: 'linked-with-empty-peer-deps',
+    version: '1.0.0',
+    peerDependencies: {},
+  })
+
+  process.chdir('linked-with-empty-peer-deps')
+
+  const linkOpts = {
+    ...DEFAULT_OPTS,
+    bin: path.join(globalDir, 'bin'),
+    dir: globalDir,
+  }
+  await link.handler({
+    ...linkOpts,
+  })
+
+  process.chdir('..')
+  process.chdir('project')
+
+  await link.handler({
+    ...linkOpts,
+  }, ['linked-with-empty-peer-deps'])
+
+  expect(warnMock).not.toHaveBeenCalledWith(expect.objectContaining({
+    message: expect.stringContaining('has the following peerDependencies specified in its package.json'),
+  }))
+
+  warnMock.mockRestore()
+})