fix: use headless install for injected self-referencing file: dependencies (#10714)

When a package has an injected self-referencing dependency (e.g.
"pkg": "file:" with dependenciesMeta injected: true), the lockfile
resolves it as "link:". The linkedPackagesAreUpToDate() function
incorrectly reported these projects as not up-to-date because
refToRelative() returns null for link: refs, causing pnpm to skip
the fast headless install path and do full resolution instead.

.changeset/fix-headless-install-injected-self-ref.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/lockfile.verification": patch
+"pnpm": patch
+---
+
+Fix headless install not being used when a project has an injected self-referencing `file:` dependency that resolves to `link:` in the lockfile.

lockfile/verification/src/linkedPackagesAreUpToDate.ts

@@ -52,6 +52,10 @@ export async function linkedPackagesAreUpToDate (
           if (!currentSpec) return true
           const lockfileRef = lockfileDeps[depName]
           if (refIsLocalDirectory(project.snapshot.specifiers[depName])) {
+            // When a file: specifier resolves to link: in the lockfile
+            // (e.g. injected self-references), it's a local link with no
+            // entry in the packages section. Treat it as up-to-date.
+            if (lockfileRef.startsWith('link:')) return true
             const depPath = refToRelative(lockfileRef, depName)
             return depPath != null && isLocalFileDepUpdated(lockfileDir, lockfilePackages?.[depPath])
           }

lockfile/verification/test/allProjectsAreUpToDate.test.ts

@@ -867,6 +867,52 @@ test('allProjectsAreUpToDate(): returns true if one of the importers is not pres
   })).toBeTruthy()
 })
 
+test('allProjectsAreUpToDate(): returns true for injected self-referencing file: dependency resolved as link:', async () => {
+  expect(await allProjectsAreUpToDate([
+    {
+      id: 'can-link' as ProjectId,
+      manifest: {
+        name: 'can-link',
+        version: '2.0.0',
+        dependenciesMeta: {
+          'can-link': {
+            injected: true,
+          },
+        },
+        devDependencies: {
+          'can-link': 'file:',
+        },
+      },
+      rootDir: 'can-link' as ProjectRootDir,
+    },
+  ], {
+    autoInstallPeers: false,
+    catalogs: {},
+    excludeLinksFromLockfile: false,
+    linkWorkspacePackages: false,
+    wantedLockfile: {
+      importers: {
+        ['can-link' as ProjectId]: {
+          dependenciesMeta: {
+            'can-link': {
+              injected: true,
+            },
+          },
+          devDependencies: {
+            'can-link': 'link:',
+          },
+          specifiers: {
+            'can-link': 'file:',
+          },
+        },
+      },
+      lockfileVersion: LOCKFILE_VERSION,
+    },
+    workspacePackages: new Map(),
+    lockfileDir: '',
+  })).toBeTruthy()
+})
+
 test('allProjectsAreUpToDate(): returns false if the lockfile is broken, the resolved versions do not satisfy the ranges', async () => {
   expect(await allProjectsAreUpToDate([
     {