fix: pnpm init skips devEngines.packageManager in workspace subpackages (#11285)

The devEngines.packageManager field should only live at the workspace root.
When init runs inside a subpackage, the field is now omitted.

.changeset/init-skip-dev-engines-in-subpackage.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/workspace.commands": patch
+"pnpm": patch
+---
+
+`pnpm init` no longer adds the `devEngines.packageManager` field when run inside a workspace subpackage. The field is only added to the workspace root's `package.json`.

workspace/commands/src/init.ts

@@ -59,6 +59,7 @@ export type InitOptions =
   & Partial<Pick<Config,
   | 'initPackageManager'
   | 'initType'
+  | 'workspaceDir'
   >> & {
     bare?: boolean
     initAuthorName?: string
@@ -77,10 +78,13 @@ export async function handler (opts: InitOptions, params?: string[]): Promise<st
   // Using cwd instead of the dir option because the dir option
   // is set to the first parent directory that has a package.json file
   // But --dir option from cliOptions should be respected.
-  const manifestPath = path.join(opts.cliOptions.dir ?? process.cwd(), 'package.json')
+  const initDir = opts.cliOptions.dir ?? process.cwd()
+  const manifestPath = path.join(initDir, 'package.json')
   if (fs.existsSync(manifestPath)) {
     throw new PnpmError('PACKAGE_JSON_EXISTS', 'package.json already exists')
   }
+  const isWorkspaceSubpackage = opts.workspaceDir != null &&
+    path.resolve(opts.workspaceDir) !== path.resolve(initDir)
   const manifest: ProjectManifest = opts.bare
     ? {}
     : {
@@ -102,7 +106,7 @@ export async function handler (opts: InitOptions, params?: string[]): Promise<st
 
   const initConfig = getInitConfig(opts)
   const packageJson = { ...manifest, ...initConfig }
-  if (opts.initPackageManager) {
+  if (opts.initPackageManager && !isWorkspaceSubpackage) {
     packageJson.devEngines = {
       ...packageJson.devEngines,
       packageManager: {

workspace/commands/test/init.test.ts

@@ -90,6 +90,38 @@ test('init a new package.json with init-package-manager=false', async () => {
   expect(manifest).not.toHaveProperty('devEngines')
 })
 
+test('init a new package.json in a workspace subpackage does not add devEngines', async () => {
+  prepareEmpty()
+  const workspaceDir = process.cwd()
+  const subpackageDir = path.join(workspaceDir, 'packages/foo')
+  fs.mkdirSync(subpackageDir, { recursive: true })
+  await init.handler({
+    cliOptions: { dir: subpackageDir },
+    initPackageManager: true,
+    workspaceDir,
+  })
+  const manifest = loadJsonFileSync<ProjectManifest>(path.join(subpackageDir, 'package.json'))
+  expect(manifest).toBeTruthy()
+  expect(manifest).not.toHaveProperty('devEngines')
+  expect(manifest).not.toHaveProperty('packageManager')
+})
+
+test('init a new package.json at the workspace root adds devEngines', async () => {
+  prepareEmpty()
+  const workspaceDir = process.cwd()
+  await init.handler({
+    cliOptions: {},
+    initPackageManager: true,
+    workspaceDir,
+  })
+  const manifest = loadJsonFileSync<ProjectManifest>(path.resolve('package.json'))
+  expect(manifest.devEngines?.packageManager).toEqual({
+    name: 'pnpm',
+    version: expect.stringMatching(/^\^\d+\.\d+\.\d+/),
+    onFail: 'download',
+  })
+})
+
 test('init a new package.json with init-type=module', async () => {
   prepareEmpty()
   await init.handler({ cliOptions: {}, initType: 'module' })