Merge d5bd7e8c9a into a7487c7e89

README.md

@@ -44,7 +44,7 @@ If `run_install` is a YAML string representation of either an object or an array
 
 ### `package_json_file`
 
-**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json` to read "packageManager" configuration.
+**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json`/[`package.yaml`](https://github.com/pnpm/pnpm/pull/1799) to read "packageManager" configuration.
 
 ### `standalone`
 

src/install-pnpm/run.ts

@@ -5,6 +5,7 @@ import { readFileSync } from 'fs'
 import path from 'path'
 import { execPath } from 'process'
 import util from 'util'
+import * as yaml from 'yaml'
 import { Inputs } from '../inputs'
 import YAML from 'yaml'
 
@@ -83,10 +84,18 @@ Otherwise, please specify the pnpm version in the action configuration.`)
   }
 
   if (typeof packageManager !== 'string') {
-    throw new Error(`No pnpm version is specified.
+    if (GITHUB_WORKSPACE) {
+      try {
+        const { lockfileVersion } = yaml.parse(readFileSync(path.join(GITHUB_WORKSPACE, 'pnpm-lock.yaml'), 'utf8'))
+        const version = getPnpmVersionFromLockfile(lockfileVersion);
+        return `${ standalone ? '@pnpm/exe' : 'pnpm' }@${version}`
+      } catch (error: unknown) {
+        throw new Error(`No pnpm version is specified.
 Please specify it by one of the following ways:
   - in the GitHub Action config with the key "version"
   - in the package.json with the key "packageManager"`)
+      }
+    }
   }
 
   if (!packageManager.startsWith('pnpm@')) {
@@ -100,4 +109,21 @@ Please specify it by one of the following ways:
   return packageManager
 }
 
+function getPnpmVersionFromLockfile(
+  lockfileVersion: string | undefined
+): string | undefined {
+  switch (true) {
+    case lockfileVersion === '5.3':
+      return 'latest-6';
+    case lockfileVersion === '5.4':
+      return 'latest-7';
+    case lockfileVersion === '6.0' || lockfileVersion === '6.1':
+      return 'latest-8';
+    case lockfileVersion === '7.0' || lockfileVersion === '9.0':
+      return 'latest-9';
+    default:
+      return undefined;
+  }
+}
+
 export default runSelfInstaller