fix(install): exit with an error when no package.json is found (#4614)

close #4609

.changeset/hungry-toes-cheat.md

@@ -0,0 +1,6 @@
+---
+"pnpm": major
+"@pnpm/plugin-commands-installation": patch
+---
+
+Exit with an error when running `pnpm install` in a directory that has no `package.json` file in it (and in parent directories) [#4609](https://github.com/pnpm/pnpm/issues/4609).

packages/plugin-commands-installation/src/installDeps.ts

@@ -168,8 +168,8 @@ when running add/update with the --workspace option')
 
   let { manifest, writeProjectManifest } = await tryReadProjectManifest(opts.dir, opts)
   if (manifest === null) {
-    if (opts.update) {
-      throw new PnpmError('NO_IMPORTER_MANIFEST', 'No package.json found')
+    if (opts.update === true || params.length === 0) {
+      throw new PnpmError('NO_PKG_MANIFEST', `No package.json found in ${opts.dir}`)
     }
     manifest = {}
   }

packages/plugin-commands-installation/test/install.ts

@@ -0,0 +1,26 @@
+import path from 'path'
+import { add, install } from '@pnpm/plugin-commands-installation'
+import { prepareEmpty } from '@pnpm/prepare'
+import { DEFAULT_OPTS } from './utils'
+
+test('install fails if no package.json is found', async () => {
+  prepareEmpty()
+
+  await expect(install.handler({
+    ...DEFAULT_OPTS,
+    dir: process.cwd(),
+  })).rejects.toThrow(/No package\.json found/)
+})
+
+test('install does not fail when a new package is added', async () => {
+  prepareEmpty()
+
+  await add.handler({
+    ...DEFAULT_OPTS,
+    dir: process.cwd(),
+  }, ['is-positive@1.0.0'])
+
+  const pkg = await import(path.resolve('package.json'))
+
+  expect(pkg?.dependencies).toStrictEqual({ 'is-positive': '1.0.0' })
+})