Fix getPackageManager logic with workspaces

Author: gonzaloriestra

packages/cli-kit/src/public/node/node-package-manager.test.ts

@@ -878,6 +878,19 @@ describe('getPackageManager', () => {
     })
   })
 
+  test('finds pnpm from a nested workspace package when the lockfile is only at the repo root', async () => {
+    await inTemporaryDirectory(async (tmpDir) => {
+      await writePackageJSON(tmpDir, {name: 'root'})
+      await writeFile(joinPath(tmpDir, 'pnpm-lock.yaml'), '')
+      const nested = joinPath(tmpDir, 'extensions', 'cart-transformer')
+      await mkdir(nested)
+      await writePackageJSON(nested, {name: 'cart-transformer'})
+
+      const packageManager = await getPackageManager(nested)
+      expect(packageManager).toEqual('pnpm')
+    })
+  })
+
   test('falls back to packageManagerFromUserAgent when no package.json is found', async () => {
     await inTemporaryDirectory(async (tmpDir) => {
       // Given — no package.json in tmpDir, stub user agent to yarn

packages/cli-kit/src/public/node/node-package-manager.ts

@@ -1,7 +1,7 @@
 import {AbortError, BugError} from './error.js'
 import {AbortController, AbortSignal} from './abort.js'
 import {exec} from './system.js'
-import {fileExists, readFile, writeFile, findPathUp, glob} from './fs.js'
+import {fileExists, readFile, writeFile, findPathUp, glob, fileExistsSync} from './fs.js'
 import {dirname, joinPath} from './path.js'
 import {runWithTimer} from './metadata.js'
 import {inferPackageManagerForGlobalCLI} from './is-global.js'
@@ -111,22 +111,26 @@ export function packageManagerFromUserAgent(env = process.env): PackageManager {
 
 /**
  * Returns the dependency manager used in a directory.
+ * Walks upward from `fromDirectory` so workspace packages (e.g. `extensions/my-fn/package.json`)
+ * still resolve to the repo root lockfile (`pnpm-lock.yaml`), not `npm` when only the root has the lock.
  * @param fromDirectory - The starting directory
  * @returns The dependency manager
  */
 export async function getPackageManager(fromDirectory: string): Promise<PackageManager> {
-  const packageJsonPath = await findPathUp('package.json', {cwd: fromDirectory, type: 'file'})
-  if (!packageJsonPath) {
-    return packageManagerFromUserAgent()
+  let current = fromDirectory
+  outputDebug(outputContent`Looking for a lockfile in ${outputToken.path(current)}...`)
+  while (true) {
+    outputDebug(outputContent`Looking for a lockfile in ${outputToken.path(current)}...`)
+    if (fileExistsSync(joinPath(current, yarnLockfile))) return 'yarn'
+    if (fileExistsSync(joinPath(current, pnpmLockfile))) return 'pnpm'
+    if (fileExistsSync(joinPath(current, bunLockfile))) return 'bun'
+    if (fileExistsSync(joinPath(current, npmLockfile))) return 'npm'
+    const parent = dirname(current)
+    if (parent === current) break
+    current = parent
   }
 
-  const directory = dirname(packageJsonPath)
-  outputDebug(outputContent`Obtaining the dependency manager in directory ${outputToken.path(directory)}...`)
-
-  if (await fileExists(joinPath(directory, yarnLockfile))) return 'yarn'
-  if (await fileExists(joinPath(directory, pnpmLockfile))) return 'pnpm'
-  if (await fileExists(joinPath(directory, bunLockfile))) return 'bun'
-  return 'npm'
+  return packageManagerFromUserAgent()
 }
 
 interface InstallNPMDependenciesRecursivelyOptions {