fix: local dependencies pointing to a symlink (#6854)

.changeset/eight-countries-poke.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/symlink-dependency": patch
+"pnpm": patch
+---
+
+When dealing with a local dependency that is a path to a symlink, a new symlink should be created to the original symlink, not to the actual directory location.

fs/symlink-dependency/src/symlinkDirectRootDependency.ts

@@ -4,7 +4,6 @@ import {
   type DependencyType,
   rootLogger,
 } from '@pnpm/core-loggers'
-import { globalWarn } from '@pnpm/logger'
 import { type DependenciesField } from '@pnpm/types'
 import symlinkDir from 'symlink-dir'
 
@@ -44,25 +43,13 @@ export async function symlinkDirectRootDependency (
     }
   }
 
-  let dependencyRealLocation!: string
-  try {
-    dependencyRealLocation = await fs.realpath(dependencyLocation)
-  } catch (err: any) { // eslint-disable-line
-    if (err.code !== 'ENOENT') throw err
-    globalWarn(`Local dependency not found at ${dependencyLocation}`)
-    // Sometimes the linked in local package does not exist during installation
-    // and is created later via a build script.
-    // That is why we create the symlink even if the target directory does not exist.
-    dependencyRealLocation = dependencyLocation
-  }
-
   const dest = path.join(destModulesDirReal, importAs)
-  const { reused } = await symlinkDir(dependencyRealLocation, dest)
+  const { reused } = await symlinkDir(dependencyLocation, dest)
   if (reused) return // if the link was already present, don't log
   rootLogger.debug({
     added: {
       dependencyType: opts.fromDependenciesField && DEP_TYPE_BY_DEPS_FIELD_NAME[opts.fromDependenciesField] as DependencyType,
-      linkedFrom: dependencyRealLocation,
+      linkedFrom: dependencyLocation,
       name: importAs,
       realName: opts.linkedPackage.name,
       version: opts.linkedPackage.version,

pkg-manager/core/test/install/local.ts

@@ -59,6 +59,17 @@ test('local file', async () => {
   })
 })
 
+test('a symlink to a symlink to a local dependency is preserved', async () => {
+  prepareEmpty()
+  const localPkgDir = path.resolve('..', 'local-pkg')
+  f.copy('local-pkg', localPkgDir)
+  await symlinkDir(localPkgDir, path.resolve('../symlink'))
+
+  await addDependenciesToPackage({}, ['link:../symlink'], await testDefaults())
+
+  expect(await fs.readlink(path.resolve('node_modules/local-pkg'))).toContain('symlink')
+})
+
 test('local directory with no package.json', async () => {
   const project = prepareEmpty()
   await fs.mkdir('pkg')