fix(#1357): Gracefully handle missing pnpm installation during cache

This change prevents the action from failing immediately when pnpm is specified
in packageManager but not yet installed (e.g., when using corepack).

Changes:
- Add isPackageManagerInstalled() function to check if a package manager exists
- Update restoreCache to skip caching with a warning if package manager not found
- Update cachePackages to skip cache save with a warning if package manager not found
- This allows workflows to continue instead of failing
- Users can either install pnpm first or disable caching with package-manager-cache: false

Fixes #1357
Related: https://github.com/actions/setup-node/issues/1357

dist/cache-save/index.js

@@ -44084,6 +44084,14 @@ const cachePackages = async (packageManager) => {
         core.debug(`Caching for '${packageManager}' is not supported`);
         return;
     }
+    // Check if the package manager is installed before attempting to save cache
+    // This prevents cache save failures for package managers that may not be installed
+    const isInstalled = await (0, cache_utils_1.isPackageManagerInstalled)(packageManager);
+    if (!isInstalled) {
+        core.warning(`Package manager '${packageManager}' was not found in the PATH. ` +
+            `Skipping cache save.`);
+        return;
+    }
     if (!cachePaths.length) {
         // TODO: core.getInput has a bug - it can return undefined despite its definition (tests only?)
         //       export declare function getInput(name: string, options?: InputOptions): string;
@@ -44147,7 +44155,7 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
     return (mod && mod.__esModule) ? mod : { "default": mod };
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.repoHasYarnBerryManagedDependencies = exports.getCacheDirectories = exports.resetProjectDirectoriesMemoized = exports.getPackageManagerInfo = exports.getCommandOutputNotEmpty = exports.getCommandOutput = exports.supportedPackageManagers = void 0;
+exports.repoHasYarnBerryManagedDependencies = exports.getCacheDirectories = exports.resetProjectDirectoriesMemoized = exports.isPackageManagerInstalled = exports.getPackageManagerInfo = exports.getCommandOutputNotEmpty = exports.getCommandOutput = exports.supportedPackageManagers = void 0;
 exports.isGhes = isGhes;
 exports.isCacheFeatureAvailable = isCacheFeatureAvailable;
 const core = __importStar(__nccwpck_require__(37484));
@@ -44218,6 +44226,25 @@ const getPackageManagerInfo = async (packageManager) => {
     }
 };
 exports.getPackageManagerInfo = getPackageManagerInfo;
+/**
+ * Checks if a package manager is installed and available on the PATH
+ * This helps prevent cache failures when a package manager is specified
+ * but not yet installed (e.g., pnpm via corepack)
+ * See: https://github.com/actions/setup-node/issues/1357
+ */
+const isPackageManagerInstalled = async (packageManager) => {
+    try {
+        const { exitCode } = await exec.getExecOutput(`${packageManager} --version`, undefined, {
+            ignoreReturnCode: true,
+            silent: true
+        });
+        return exitCode === 0;
+    }
+    catch {
+        return false;
+    }
+};
+exports.isPackageManagerInstalled = isPackageManagerInstalled;
 /**
  * getProjectDirectoriesFromCacheDependencyPath is called twice during `restoreCache`
  *  - first through `getCacheDirectories`

dist/setup/index.js

@@ -53696,6 +53696,16 @@ const restoreCache = async (packageManager, cacheDependencyPath) => {
     if (!packageManagerInfo) {
         throw new Error(`Caching for '${packageManager}' is not supported`);
     }
+    // Check if the package manager is installed before attempting to cache
+    // This prevents cache failures for package managers that need to be installed first
+    // See: https://github.com/actions/setup-node/issues/1357
+    const isInstalled = await (0, cache_utils_1.isPackageManagerInstalled)(packageManager);
+    if (!isInstalled) {
+        core.warning(`Package manager '${packageManager}' was not found in the PATH. ` +
+            `Skipping cache restore. Please ensure the package manager is installed ` +
+            `before running this action or set 'package-manager-cache: false' to disable caching.`);
+        return;
+    }
     const platform = process.env.RUNNER_OS;
     const arch = os_1.default.arch();
     const cachePaths = await (0, cache_utils_1.getCacheDirectories)(packageManagerInfo, cacheDependencyPath);
@@ -53785,7 +53795,7 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
     return (mod && mod.__esModule) ? mod : { "default": mod };
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.repoHasYarnBerryManagedDependencies = exports.getCacheDirectories = exports.resetProjectDirectoriesMemoized = exports.getPackageManagerInfo = exports.getCommandOutputNotEmpty = exports.getCommandOutput = exports.supportedPackageManagers = void 0;
+exports.repoHasYarnBerryManagedDependencies = exports.getCacheDirectories = exports.resetProjectDirectoriesMemoized = exports.isPackageManagerInstalled = exports.getPackageManagerInfo = exports.getCommandOutputNotEmpty = exports.getCommandOutput = exports.supportedPackageManagers = void 0;
 exports.isGhes = isGhes;
 exports.isCacheFeatureAvailable = isCacheFeatureAvailable;
 const core = __importStar(__nccwpck_require__(37484));
@@ -53856,6 +53866,25 @@ const getPackageManagerInfo = async (packageManager) => {
     }
 };
 exports.getPackageManagerInfo = getPackageManagerInfo;
+/**
+ * Checks if a package manager is installed and available on the PATH
+ * This helps prevent cache failures when a package manager is specified
+ * but not yet installed (e.g., pnpm via corepack)
+ * See: https://github.com/actions/setup-node/issues/1357
+ */
+const isPackageManagerInstalled = async (packageManager) => {
+    try {
+        const { exitCode } = await exec.getExecOutput(`${packageManager} --version`, undefined, {
+            ignoreReturnCode: true,
+            silent: true
+        });
+        return exitCode === 0;
+    }
+    catch {
+        return false;
+    }
+};
+exports.isPackageManagerInstalled = isPackageManagerInstalled;
 /**
  * getProjectDirectoriesFromCacheDependencyPath is called twice during `restoreCache`
  *  - first through `getCacheDirectories`

src/cache-restore.ts

@@ -9,6 +9,7 @@ import {State} from './constants';
 import {
   getCacheDirectories,
   getPackageManagerInfo,
+  isPackageManagerInstalled,
   repoHasYarnBerryManagedDependencies,
   PackageManagerInfo
 } from './cache-utils';
@@ -21,6 +22,20 @@ export const restoreCache = async (
   if (!packageManagerInfo) {
     throw new Error(`Caching for '${packageManager}' is not supported`);
   }
+
+  // Check if the package manager is installed before attempting to cache
+  // This prevents cache failures for package managers that need to be installed first
+  // See: https://github.com/actions/setup-node/issues/1357
+  const isInstalled = await isPackageManagerInstalled(packageManager);
+  if (!isInstalled) {
+    core.warning(
+      `Package manager '${packageManager}' was not found in the PATH. ` +
+        `Skipping cache restore. Please ensure the package manager is installed ` +
+        `before running this action or set 'package-manager-cache: false' to disable caching.`
+    );
+    return;
+  }
+
   const platform = process.env.RUNNER_OS;
   const arch = os.arch();
 

src/cache-save.ts

@@ -2,7 +2,7 @@ import * as core from '@actions/core';
 import * as cache from '@actions/cache';
 
 import {State} from './constants';
-import {getPackageManagerInfo} from './cache-utils';
+import {getPackageManagerInfo, isPackageManagerInstalled} from './cache-utils';
 
 // Catch and log any unhandled exceptions.  These exceptions can leak out of the uploadChunk method in
 // @actions/toolkit when a failed upload closes the file descriptor causing any in-process reads to
@@ -45,6 +45,17 @@ const cachePackages = async (packageManager: string) => {
     return;
   }
 
+  // Check if the package manager is installed before attempting to save cache
+  // This prevents cache save failures for package managers that may not be installed
+  const isInstalled = await isPackageManagerInstalled(packageManager);
+  if (!isInstalled) {
+    core.warning(
+      `Package manager '${packageManager}' was not found in the PATH. ` +
+        `Skipping cache save.`
+    );
+    return;
+  }
+
   if (!cachePaths.length) {
     // TODO: core.getInput has a bug - it can return undefined despite its definition (tests only?)
     //       export declare function getInput(name: string, options?: InputOptions): string;

src/cache-utils.ts

@@ -110,6 +110,30 @@ export const getPackageManagerInfo = async (packageManager: string) => {
   }
 };
 
+/**
+ * Checks if a package manager is installed and available on the PATH
+ * This helps prevent cache failures when a package manager is specified
+ * but not yet installed (e.g., pnpm via corepack)
+ * See: https://github.com/actions/setup-node/issues/1357
+ */
+export const isPackageManagerInstalled = async (
+  packageManager: string
+): Promise<boolean> => {
+  try {
+    const {exitCode} = await exec.getExecOutput(
+      `${packageManager} --version`,
+      undefined,
+      {
+        ignoreReturnCode: true,
+        silent: true
+      }
+    );
+    return exitCode === 0;
+  } catch {
+    return false;
+  }
+};
+
 /**
  * getProjectDirectoriesFromCacheDependencyPath is called twice during `restoreCache`
  *  - first through `getCacheDirectories`