initial commit

.github/workflows/basic-validation.yml

@@ -6,7 +6,7 @@ on:
       - '**.md'
   push:
     branches:
-      - main
+      - check-686
       - releases/*
     paths-ignore:
       - '**.md'

.github/workflows/check-dist.yml

@@ -3,7 +3,7 @@ name: Check dist
 on:
   push:
     branches:
-      - main
+      - check-686
     paths-ignore:
       - '**.md'
   pull_request:

.github/workflows/codeql-analysis.yml

@@ -2,7 +2,7 @@ name: CodeQL analysis
 
 on:
   push:
-    branches: [main]
+    branches: [check-686]
   pull_request:
     branches: [main]
   schedule:

.github/workflows/e2e-cache.yml

@@ -6,7 +6,7 @@ on:
       - '**.md'
   push:
     branches:
-      - main
+      - check-686
       - releases/*
     paths-ignore:
       - '**.md'
@@ -243,3 +243,43 @@ jobs:
           cache-dependency-path: |
             sub2/*.lock
             sub3/*.lock
+
+  test-cache-auto-enabled:
+    name: Test Cache Auto-Enabled
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest, macos-13]
+        node-version: [18, 20, 22]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Change directory to __tests__/data
+        run: cd __tests__/data
+      - name: Setup Node
+        uses: ./
+        with:
+          node-version: ${{ matrix.node-version }}
+      - name: Install dependencies
+        run: npm install
+
+  test-cache-explicitly-disabled:
+    name: Test Cache Explicitly Disabled
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest, macos-13]
+        node-version: [18, 20, 22]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Change directory to __tests__/data
+        run: cd __tests__/data
+      - name: Setup Node
+        uses: ./
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: ''
+      - name: Verify node and npm
+        run: __tests__/verify-node.sh "${{ matrix.node-version }}"
+        shell: bash

.github/workflows/licensed.yml

@@ -3,7 +3,7 @@ name: Licensed
 on:
   push:
     branches:
-      - main
+      - check-686
   pull_request:
     branches:
       - main

.github/workflows/proxy.yml

@@ -6,7 +6,7 @@ on:
       - '**.md'
   push:
     branches:
-      - main
+      - check-686
       - releases/*
     paths-ignore:
       - '**.md'

.github/workflows/versions.yml

@@ -6,7 +6,7 @@ on:
       - '**.md'
   push:
     branches:
-      - main
+      - check-686
       - releases/*
     paths-ignore:
       - '**.md'

README.md

@@ -135,7 +135,8 @@ It's **always** recommended to commit the lockfile of your package manager for s
 
 ## Caching global packages data
 
-The action has a built-in functionality for caching and restoring dependencies. It uses [actions/cache](https://github.com/actions/cache) under the hood for caching global packages data but requires less configuration settings. Supported package managers are `npm`, `yarn`, `pnpm` (v6.10+). The `cache` input is optional, and caching is turned off by default.
+The action has a built-in functionality for caching and restoring dependencies. It uses [actions/cache](https://github.com/actions/cache) under the hood for caching global packages data but requires less configuration settings. Supported package managers are `npm`, `yarn`, `pnpm` (v6.10+). The `cache` input is optional. If not set, caching is automatically enabled if a supported package manager is detected in your `package.json` (`devEngines.packageManager.name` or `packageManager` field).  
+If set to `''` (empty string), caching is explicitly disabled, even if a package manager is present.
 
 The action defaults to search for the dependency file (`package-lock.json`, `npm-shrinkwrap.json` or `yarn.lock`) in the repository root, and uses its hash as a part of the cache key. Use `cache-dependency-path` for cases when multiple dependency files are used, or they are located in different subdirectories.
 

__tests__/data/package.json

@@ -1,4 +1,9 @@
 {
+  "devEngines": {
+    "packageManager": {
+      "name": "npm"
+    }
+  },
   "engines": {
     "node": "^20.0.0"
   }

__tests__/main.test.ts

@@ -240,6 +240,15 @@ describe('main tests', () => {
   });
 
   describe('cache on GHES', () => {
+    beforeEach(() => {
+      // Reset mocks and environment variables before each test
+      jest.resetModules();
+      jest.clearAllMocks();
+      jest.spyOn(core, 'saveState').mockImplementation(() => {});
+      jest.spyOn(core, 'warning').mockImplementation(() => {});
+      delete process.env['GITHUB_SERVER_URL'];
+    });
+
     it('Should throw an error, because cache is not supported', async () => {
       inputs['node-version'] = '12';
       inputs['cache'] = 'npm';
@@ -253,6 +262,9 @@ describe('main tests', () => {
       process.env['GITHUB_SERVER_URL'] = 'https://www.test.com';
       isCacheActionAvailable.mockImplementation(() => false);
 
+      // Mock package.json with no packageManager field
+      jest.spyOn(fs, 'readFileSync').mockReturnValue(JSON.stringify({}));
+
       await main.run();
 
       expect(warningSpy).toHaveBeenCalledWith(
@@ -273,11 +285,107 @@ describe('main tests', () => {
       process.env['GITHUB_SERVER_URL'] = '';
       isCacheActionAvailable.mockImplementation(() => false);
 
+      // Mock package.json with no packageManager field
+      jest.spyOn(fs, 'readFileSync').mockReturnValue(JSON.stringify({}));
+
       await main.run();
 
       expect(warningSpy).toHaveBeenCalledWith(
         'The runner was not able to contact the cache service. Caching will be skipped'
       );
     });
+
+    it('Should enable caching by default when packageManager field is defined', async () => {
+      inputs['node-version'] = '12';
+      inputs['cache'] = undefined; // User did not specify cache
+
+      inSpy.mockImplementation(name => inputs[name]);
+      const toolPath = path.normalize('/cache/node/18.0.0/x64');
+      findSpy.mockImplementation(() => toolPath);
+
+      process.env['GITHUB_SERVER_URL'] = 'https://www.test.com';
+      isCacheActionAvailable.mockImplementation(() => true);
+
+      // packageManager in package.json
+      (fs.readFileSync as jest.Mock).mockReturnValue(
+        JSON.stringify({
+          packageManager: 'yarn@3.2.0'
+        })
+      );
+
+      await main.run();
+
+      // Should enable caching (saveState called with 'yarn')
+      expect(core.saveState).toHaveBeenCalledWith(expect.anything(), 'yarn');
+    });
+
+    it('Should enable cache if devEngines.packageManager field is present', async () => {
+      inputs['node-version'] = '12';
+      inputs['cache'] = undefined; // Explicitly opt-in via package.json
+
+      inSpy.mockImplementation(name => inputs[name]);
+      findSpy.mockImplementation(() =>
+        path.normalize('/cache/node/12.16.1/x64')
+      );
+      process.env['GITHUB_SERVER_URL'] = 'https://www.test.com';
+      isCacheActionAvailable.mockImplementation(() => true);
+
+      // devEngines.packageManager in package.json
+      (fs.readFileSync as jest.Mock).mockReturnValue(
+        JSON.stringify({
+          devEngines: {
+            packageManager: {name: 'pnpm'}
+          }
+        })
+      );
+
+      await main.run();
+
+      // Should enable caching (saveState called with 'pnpm')
+      expect(core.saveState).toHaveBeenCalledWith(expect.anything(), 'pnpm');
+    });
+
+    it('Should NOT enable caching when neither cache nor packageManager is set', async () => {
+      inputs['node-version'] = '12';
+      inputs['cache'] = undefined;
+
+      inSpy.mockImplementation(name => inputs[name]);
+      findSpy.mockImplementation(() =>
+        path.normalize('/cache/node/12.16.1/x64')
+      );
+      process.env['GITHUB_SERVER_URL'] = 'https://www.test.com';
+      isCacheActionAvailable.mockImplementation(() => true);
+
+      // package.json with no cache info
+      (fs.readFileSync as jest.Mock).mockReturnValue(JSON.stringify({}));
+
+      await main.run();
+
+      expect(core.saveState).not.toHaveBeenCalled();
+    });
+
+    it('Should NOT enable caching when cache is explicitly disabled', async () => {
+      inputs['node-version'] = '12';
+      inputs['cache'] = ''; // Explicitly opt-out
+
+      inSpy.mockImplementation(name => inputs[name]);
+      findSpy.mockImplementation(() =>
+        path.normalize('/cache/node/12.16.1/x64')
+      );
+      process.env['GITHUB_SERVER_URL'] = 'https://www.test.com';
+      isCacheActionAvailable.mockImplementation(() => true);
+
+      // packageManager in package.json
+      (fs.readFileSync as jest.Mock).mockReturnValue(
+        JSON.stringify({
+          packageManager: 'yarn@3.2.0'
+        })
+      );
+
+      await main.run();
+
+      // Should NOT enable caching (saveState not called)
+      expect(core.saveState).not.toHaveBeenCalled();
+    });
   });
 });

src/main.ts

@@ -1,6 +1,7 @@
 import * as core from '@actions/core';
 
 import os from 'os';
+import fs from 'fs';
 
 import * as auth from './authutil';
 import * as path from 'path';
@@ -63,10 +64,21 @@ export async function run() {
       auth.configAuthentication(registryUrl, alwaysAuth);
     }
 
-    if (cache && isCacheFeatureAvailable()) {
-      core.saveState(State.CachePackageManager, cache);
+    const packageManagerFromManifest = getNameFromPackageManagerField();
+    if (
+      cache !== '' &&
+      isCacheFeatureAvailable() &&
+      (cache !== undefined || packageManagerFromManifest)
+    ) {
       const cacheDependencyPath = core.getInput('cache-dependency-path');
-      await restoreCache(cache, cacheDependencyPath);
+      const packageManager =
+        cache !== undefined ? cache : packageManagerFromManifest;
+      if (!packageManager) {
+        // This should NOT happen due to your if, but this satisfies TypeScript.
+        return;
+      }
+      core.saveState(State.CachePackageManager, packageManager);
+      await restoreCache(packageManager, cacheDependencyPath);
     }
 
     const matchersPath = path.join(__dirname, '../..', '.github');
@@ -117,3 +129,12 @@ function resolveVersionInput(): string {
 
   return version;
 }
+
+export function getNameFromPackageManagerField(): string | undefined {
+  // Check devEngines.packageManager first
+  const packageJson = JSON.parse(fs.readFileSync('package.json', 'utf-8'));
+  return (
+    packageJson.devEngines?.packageManager?.name ||
+    packageJson.packageManager?.replace(/^[^a-zA-Z0-9]+/, '').split('@')[0]
+  );
+}