update error wording (#2467)

* getting ready for checkout v7 release

* update changelog wording

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

.github/workflows/publish-immutable-actions.yml

@@ -17,4 +17,4 @@ jobs:
         uses: actions/checkout@v6
       - name: Publish
         id: publish
-        uses: actions/publish-immutable-action@0.0.3
+        uses: actions/publish-immutable-action@v0.0.4

.licensed.yml

@@ -12,3 +12,4 @@ allowed:
 
 reviewed:
   npm:
+    - "@actions/http-client" # MIT

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## v7.0.0
+* Block checking out fork PR for pull_request_target and workflow_run by @aiqiaoy in https://github.com/actions/checkout/pull/2454
+* Bump actions/publish-immutable-action from 0.0.3 to 0.0.4 in the minor-actions-dependencies group across 1 directory by @dependabot[bot] in https://github.com/actions/checkout/pull/2458
+* Bump flatted from 3.3.1 to 3.4.2 by @dependabot[bot] in https://github.com/actions/checkout/pull/2460
+* Bump js-yaml from 4.1.0 to 4.2.0 by @dependabot[bot] in https://github.com/actions/checkout/pull/2461
+* Bump @actions/core and @actions/tool-cache and Remove uuid by @dependabot[bot] in https://github.com/actions/checkout/pull/2459
+* upgrade module to esm and update dependencies by @aiqiaoy in https://github.com/actions/checkout/pull/2463
+* Bump the minor-npm-dependencies group across 1 directory with 3 updates by @dependabot[bot] in https://github.com/actions/checkout/pull/2462
+
 ## v6.0.3
 * Fix checkout init for SHA-256 repositories by @yaananth in https://github.com/actions/checkout/pull/2439
 * fix: expand merge commit SHA regex and add SHA-256 test cases by @yaananth in https://github.com/actions/checkout/pull/2414

README.md

@@ -1,5 +1,14 @@
 [![Build and Test](https://github.com/actions/checkout/actions/workflows/test.yml/badge.svg)](https://github.com/actions/checkout/actions/workflows/test.yml)
 
+# Checkout v7
+
+## What's new
+
+- Safer fork pull request handling: checkout now refuses to check out fork pull request code by default when the workflow is triggered by `pull_request_target` or `workflow_run`. These triggers run with the base repository's `GITHUB_TOKEN`, secrets, and runner access, where executing a fork's code commonly leads to "pwn request" vulnerabilities.
+  - To opt in after [reviewing the risks](https://gh.io/securely-using-pull_request_target), set the new `allow-unsafe-pr-checkout: true` input.
+- Migrated `actions/checkout` to ESM to support new versions of the `@actions/*` packages.
+- Updated direct and transitive dependencies, including security fixes for known vulnerabilities.
+
 # Checkout v6
 
 ## What's new
@@ -15,7 +24,6 @@
 - Updated to the node24 runtime
   - This requires a minimum Actions Runner version of [v2.327.1](https://github.com/actions/runner/releases/tag/v2.327.1) to run.
 
-
 # Checkout v4
 
 This action checks-out your repository under `$GITHUB_WORKSPACE`, so your workflow can access it.
@@ -52,7 +60,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 <!-- start usage -->
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     # Repository name with owner. For example, actions/checkout
     # Default: ${{ github.repository }}
@@ -160,6 +168,15 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # running from unless specified. Example URLs are https://github.com or
     # https://my-ghes-server.example.com
     github-server-url: ''
+
+    # Required to check out fork pull request code from a workflow triggered by
+    # `pull_request_target` or `workflow_run`. These workflows run with the base
+    # repository's GITHUB_TOKEN, secrets, default-branch cache scope, and runner
+    # access; fetching and executing a fork's code in that trusted context commonly
+    # leads to "pwn request" vulnerabilities. Set to `true` only after reviewing the
+    # risks at https://gh.io/securely-using-pull_request_target.
+    # Default: false
+    allow-unsafe-pr-checkout: ''
 ```
 <!-- end usage -->
 
@@ -191,7 +208,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only the root files
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     sparse-checkout: .
 ```
@@ -199,7 +216,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only the root files and `.github` and `src` folder
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     sparse-checkout: |
       .github
@@ -209,7 +226,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only a single file
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     sparse-checkout: |
       README.md
@@ -219,7 +236,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch all history for all tags and branches
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     fetch-depth: 0
 ```
@@ -227,7 +244,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout a different branch
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     ref: my-branch
 ```
@@ -235,7 +252,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout HEAD^
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     fetch-depth: 2
 - run: git checkout HEAD^
@@ -245,12 +262,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
   with:
     path: main
 
 - name: Checkout tools repo
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
   with:
     repository: my-org/my-tools
     path: my-tools
@@ -261,10 +278,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
 
 - name: Checkout tools repo
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
   with:
     repository: my-org/my-tools
     path: my-tools
@@ -275,12 +292,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
   with:
     path: main
 
 - name: Checkout private tools
-  uses: actions/checkout@v6
+  uses: actions/checkout@v7
   with:
     repository: my-org/my-private-tools
     token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
@@ -293,7 +310,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout pull request HEAD commit instead of merge commit
 
 ```yaml
-- uses: actions/checkout@v6
+- uses: actions/checkout@v7
   with:
     ref: ${{ github.event.pull_request.head.sha }}
 ```
@@ -309,7 +326,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 ```
 
 ## Push a commit using the built-in token
@@ -320,7 +337,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - run: |
           date > generated.txt
           # Note: the following account information will not work on GHES
@@ -342,7 +359,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
         with:
           ref: ${{ github.head_ref }}
       - run: |

__test__/git-auth-helper.test.ts

@@ -1,12 +1,46 @@
-import * as core from '@actions/core'
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  beforeEach,
+  afterEach,
+  afterAll
+} from '@jest/globals'
 import * as fs from 'fs'
-import * as gitAuthHelper from '../lib/git-auth-helper'
 import * as io from '@actions/io'
 import * as os from 'os'
 import * as path from 'path'
-import * as stateHelper from '../lib/state-helper'
-import {IGitCommandManager} from '../lib/git-command-manager'
-import {IGitSourceSettings} from '../lib/git-source-settings'
+import {fileURLToPath} from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+
+// Mock @actions/core before loading git-auth-helper
+jest.unstable_mockModule('@actions/core', () => ({
+  setSecret: jest.fn(),
+  error: jest.fn(),
+  warning: jest.fn(),
+  info: jest.fn(),
+  debug: jest.fn(),
+  setFailed: jest.fn()
+}))
+
+// Mock state-helper
+jest.unstable_mockModule('../src/state-helper.js', () => ({
+  setSshKeyPath: jest.fn(),
+  setSshKnownHostsPath: jest.fn(),
+  IsPost: false,
+  RepositoryPath: ''
+}))
+
+// Dynamic imports after mocking
+const core = await import('@actions/core')
+const gitAuthHelper = await import('../src/git-auth-helper.js')
+type IGitCommandManager =
+  import('../src/git-command-manager.js').IGitCommandManager
+type IGitSourceSettings =
+  import('../src/git-source-settings.js').IGitSourceSettings
 
 const isWindows = process.platform === 'win32'
 const testWorkspace = path.join(__dirname, '_temp', 'git-auth-helper')
@@ -32,25 +66,12 @@ describe('git-auth-helper tests', () => {
   })
 
   beforeEach(() => {
-    // Mock setSecret
-    jest.spyOn(core, 'setSecret').mockImplementation((secret: string) => {})
-
-    // Mock error/warning/info/debug
-    jest.spyOn(core, 'error').mockImplementation(jest.fn())
-    jest.spyOn(core, 'warning').mockImplementation(jest.fn())
-    jest.spyOn(core, 'info').mockImplementation(jest.fn())
-    jest.spyOn(core, 'debug').mockImplementation(jest.fn())
-
-    // Mock state helper
-    jest.spyOn(stateHelper, 'setSshKeyPath').mockImplementation(jest.fn())
-    jest
-      .spyOn(stateHelper, 'setSshKnownHostsPath')
-      .mockImplementation(jest.fn())
+    jest.clearAllMocks()
   })
 
   afterEach(() => {
     // Unregister mocks
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
 
     // Restore HOME
     if (originalHome) {
@@ -229,7 +250,7 @@ describe('git-auth-helper tests', () => {
     await authHelper.configureAuth()
 
     // Assert secret
-    const setSecretSpy = core.setSecret as jest.Mock<any, any>
+    const setSecretSpy = core.setSecret as jest.Mock<any>
     expect(setSecretSpy).toHaveBeenCalledTimes(1)
     const expectedSecret = Buffer.from(
       `x-access-token:${settings.authToken}`,
@@ -529,7 +550,7 @@ describe('git-auth-helper tests', () => {
       settings.sshKey = ''
       const authHelper = gitAuthHelper.createAuthHelper(git, settings)
       await authHelper.configureAuth()
-      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any>
       mockSubmoduleForeach.mockClear() // reset calls
 
       // Act
@@ -562,7 +583,7 @@ describe('git-auth-helper tests', () => {
       settings.persistCredentials = false
       const authHelper = gitAuthHelper.createAuthHelper(git, settings)
       await authHelper.configureAuth()
-      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any>
       mockSubmoduleForeach.mockClear() // reset calls
 
       // Act
@@ -588,7 +609,7 @@ describe('git-auth-helper tests', () => {
       settings.sshKey = ''
       const authHelper = gitAuthHelper.createAuthHelper(git, settings)
       await authHelper.configureAuth()
-      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any>
       mockSubmoduleForeach.mockClear() // reset calls
 
       // Act
@@ -627,7 +648,7 @@ describe('git-auth-helper tests', () => {
       )
       const authHelper = gitAuthHelper.createAuthHelper(git, settings)
       await authHelper.configureAuth()
-      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any>
       mockSubmoduleForeach.mockClear() // reset calls
 
       // Act
@@ -809,7 +830,7 @@ describe('git-auth-helper tests', () => {
 
     // Mock getSubmoduleConfigPaths to return our fake submodules (for both configure and remove)
     const mockGetSubmoduleConfigPaths =
-      git.getSubmoduleConfigPaths as jest.Mock<any, any>
+      git.getSubmoduleConfigPaths as jest.Mock<any>
     mockGetSubmoduleConfigPaths.mockResolvedValue([
       submodule1ConfigPath,
       submodule2ConfigPath
@@ -1147,7 +1168,7 @@ async function setup(testName: string): Promise<void> {
     ),
     tryReset: jest.fn(),
     version: jest.fn()
-  }
+  } as unknown as IGitCommandManager & {env: {[key: string]: string}}
 
   settings = {
     authToken: 'some auth token',
@@ -1173,7 +1194,8 @@ async function setup(testName: string): Promise<void> {
     sshUser: '',
     workflowOrganizationId: 123456,
     setSafeDirectory: true,
-    githubServerUrl: githubServerUrl
+    githubServerUrl: githubServerUrl,
+    allowUnsafePrCheckout: false
   }
 }
 

__test__/git-command-manager.test.ts

@@ -1,26 +1,51 @@
-import * as exec from '@actions/exec'
-import * as fshelper from '../lib/fs-helper'
-import * as commandManager from '../lib/git-command-manager'
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  beforeEach,
+  afterEach,
+  afterAll
+} from '@jest/globals'
 
-let git: commandManager.IGitCommandManager
-let mockExec = jest.fn()
+// Mock @actions/exec
+const mockExec = jest.fn()
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: mockExec
+}))
+
+// Mock fs-helper
+const mockFileExistsSync = jest.fn()
+const mockDirectoryExistsSync = jest.fn()
+jest.unstable_mockModule('../src/fs-helper.js', () => ({
+  fileExistsSync: mockFileExistsSync,
+  directoryExistsSync: mockDirectoryExistsSync
+}))
+
+// Dynamic imports after mocking
+const commandManager = await import('../src/git-command-manager.js')
+type IGitCommandManager =
+  import('../src/git-command-manager.js').IGitCommandManager
+
+let git: IGitCommandManager
 
 describe('git-auth-helper tests', () => {
   beforeAll(async () => {})
 
   beforeEach(async () => {
-    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
-    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+    mockFileExistsSync.mockReset()
+    mockDirectoryExistsSync.mockReset()
   })
 
   afterEach(() => {
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
   })
 
   afterAll(() => {})
 
   it('branch list matches', async () => {
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       console.log(args, options.listeners.stdout)
 
       if (args.includes('version')) {
@@ -36,7 +61,7 @@ describe('git-auth-helper tests', () => {
 
       return 1
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
     const workingDirectory = 'test'
     const lfs = false
     const doSparseCheckout = false
@@ -53,7 +78,7 @@ describe('git-auth-helper tests', () => {
   })
 
   it('ambiguous ref name output is captured', async () => {
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       console.log(args, options.listeners.stdout)
 
       if (args.includes('version')) {
@@ -72,7 +97,7 @@ describe('git-auth-helper tests', () => {
 
       return 1
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
     const workingDirectory = 'test'
     const lfs = false
     const doSparseCheckout = false
@@ -91,9 +116,9 @@ describe('git-auth-helper tests', () => {
 
 describe('Test fetchDepth and fetchTags options', () => {
   beforeEach(async () => {
-    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
-    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
-    mockExec.mockImplementation((path, args, options) => {
+    mockFileExistsSync.mockReset()
+    mockDirectoryExistsSync.mockReset()
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       console.log(args, options.listeners.stdout)
 
       if (args.includes('version')) {
@@ -105,11 +130,11 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   afterEach(() => {
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
   })
 
   it('should call execGit with the correct arguments when fetchDepth is 0', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
     const workingDirectory = 'test'
     const lfs = false
     const doSparseCheckout = false
@@ -146,7 +171,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when fetchDepth is 0 and refSpec includes tags', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -184,7 +209,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when fetchDepth is 1', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -222,7 +247,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when fetchDepth is 1 and refSpec includes tags', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -261,7 +286,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when showProgress is true', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -299,7 +324,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when fetchDepth is 42 and showProgress is true', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -339,7 +364,7 @@ describe('Test fetchDepth and fetchTags options', () => {
   })
 
   it('should call execGit with the correct arguments when showProgress is true and refSpec includes tags', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -380,23 +405,23 @@ describe('Test fetchDepth and fetchTags options', () => {
 
 describe('repository initialization object format', () => {
   beforeEach(async () => {
-    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
-    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+    mockFileExistsSync.mockReset()
+    mockDirectoryExistsSync.mockReset()
   })
 
   afterEach(() => {
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
   })
 
   it('initializes SHA-256 repositories with the matching object format', async () => {
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       if (args.includes('version')) {
         options.listeners.stdout(Buffer.from('git version 2.50.1'))
       }
 
       return 0
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     git = await commandManager.createCommandManager('test', false, false)
 
@@ -410,14 +435,14 @@ describe('repository initialization object format', () => {
   })
 
   it('initializes SHA-1 repositories with existing default arguments', async () => {
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       if (args.includes('version')) {
         options.listeners.stdout(Buffer.from('git version 2.50.1'))
       }
 
       return 0
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     git = await commandManager.createCommandManager('test', false, false)
 
@@ -433,12 +458,12 @@ describe('repository initialization object format', () => {
 
 describe('git user-agent with orchestration ID', () => {
   beforeEach(async () => {
-    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
-    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+    mockFileExistsSync.mockReset()
+    mockDirectoryExistsSync.mockReset()
   })
 
   afterEach(() => {
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
     // Clean up environment variable to prevent test pollution
     delete process.env['ACTIONS_ORCHESTRATION_ID']
   })
@@ -448,7 +473,7 @@ describe('git user-agent with orchestration ID', () => {
     process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
 
     let capturedEnv: any = null
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       if (args.includes('version')) {
         options.listeners.stdout(Buffer.from('2.18'))
       }
@@ -456,7 +481,7 @@ describe('git user-agent with orchestration ID', () => {
       capturedEnv = options.env
       return 0
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -483,7 +508,7 @@ describe('git user-agent with orchestration ID', () => {
     process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
 
     let capturedEnv: any = null
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       if (args.includes('version')) {
         options.listeners.stdout(Buffer.from('2.18'))
       }
@@ -491,7 +516,7 @@ describe('git user-agent with orchestration ID', () => {
       capturedEnv = options.env
       return 0
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false
@@ -517,7 +542,7 @@ describe('git user-agent with orchestration ID', () => {
     delete process.env['ACTIONS_ORCHESTRATION_ID']
 
     let capturedEnv: any = null
-    mockExec.mockImplementation((path, args, options) => {
+    mockExec.mockImplementation((path: any, args: any, options: any) => {
       if (args.includes('version')) {
         options.listeners.stdout(Buffer.from('2.18'))
       }
@@ -525,7 +550,7 @@ describe('git user-agent with orchestration ID', () => {
       capturedEnv = options.env
       return 0
     })
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    // exec.exec is already mockExec
 
     const workingDirectory = 'test'
     const lfs = false

__test__/git-directory-helper.test.ts

@@ -1,9 +1,36 @@
-import * as core from '@actions/core'
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  beforeEach,
+  afterEach
+} from '@jest/globals'
 import * as fs from 'fs'
-import * as gitDirectoryHelper from '../lib/git-directory-helper'
 import * as io from '@actions/io'
 import * as path from 'path'
-import {IGitCommandManager} from '../lib/git-command-manager'
+import {fileURLToPath} from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+
+// Mock @actions/core before loading git-directory-helper
+jest.unstable_mockModule('@actions/core', () => ({
+  error: jest.fn(),
+  warning: jest.fn(),
+  info: jest.fn(),
+  debug: jest.fn(),
+  setFailed: jest.fn(),
+  startGroup: jest.fn(),
+  endGroup: jest.fn()
+}))
+
+// Dynamic imports after mocking
+const core = await import('@actions/core')
+const gitDirectoryHelper = await import('../src/git-directory-helper.js')
+
+type IGitCommandManager =
+  import('../src/git-command-manager.js').IGitCommandManager
 
 const testWorkspace = path.join(__dirname, '_temp', 'git-directory-helper')
 let repositoryPath: string
@@ -19,16 +46,11 @@ describe('git-directory-helper tests', () => {
   })
 
   beforeEach(() => {
-    // Mock error/warning/info/debug
-    jest.spyOn(core, 'error').mockImplementation(jest.fn())
-    jest.spyOn(core, 'warning').mockImplementation(jest.fn())
-    jest.spyOn(core, 'info').mockImplementation(jest.fn())
-    jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+    jest.clearAllMocks()
   })
 
   afterEach(() => {
-    // Unregister mocks
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
   })
 
   const cleansWhenCleanTrue = 'cleans when clean true'
@@ -81,7 +103,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(doesNotCheckoutDetachWhenNotAlreadyDetached)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    const mockIsDetached = git.isDetached as jest.Mock<any, any>
+    const mockIsDetached = git.isDetached as jest.Mock<any>
     mockIsDetached.mockImplementation(async () => {
       return true
     })
@@ -132,7 +154,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(removesContentsWhenCleanFails)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    let mockTryClean = git.tryClean as jest.Mock<any, any>
+    let mockTryClean = git.tryClean as jest.Mock<any>
     mockTryClean.mockImplementation(async () => {
       return false
     })
@@ -210,7 +232,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(removesContentsWhenResetFails)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    let mockTryReset = git.tryReset as jest.Mock<any, any>
+    let mockTryReset = git.tryReset as jest.Mock<any>
     mockTryReset.mockImplementation(async () => {
       return false
     })
@@ -260,7 +282,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(removesLocalBranches)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    const mockBranchList = git.branchList as jest.Mock<any, any>
+    const mockBranchList = git.branchList as jest.Mock<any>
     mockBranchList.mockImplementation(async (remote: boolean) => {
       return remote ? [] : ['local-branch-1', 'local-branch-2']
     })
@@ -291,7 +313,7 @@ describe('git-directory-helper tests', () => {
 
     //mock bad submodule
 
-    const submoduleStatus = git.submoduleStatus as jest.Mock<any, any>
+    const submoduleStatus = git.submoduleStatus as jest.Mock<any>
     submoduleStatus.mockImplementation(async (remote: boolean) => {
       return false
     })
@@ -319,7 +341,7 @@ describe('git-directory-helper tests', () => {
     await setup(doesNotCleanWhenSubmoduleStatusIsTrue)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
 
-    const submoduleStatus = git.submoduleStatus as jest.Mock<any, any>
+    const submoduleStatus = git.submoduleStatus as jest.Mock<any>
     submoduleStatus.mockImplementation(async (remote: boolean) => {
       return true
     })
@@ -381,7 +403,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(removesAncestorRemoteBranch)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    const mockBranchList = git.branchList as jest.Mock<any, any>
+    const mockBranchList = git.branchList as jest.Mock<any>
     mockBranchList.mockImplementation(async (remote: boolean) => {
       return remote ? ['origin/remote-branch-1', 'origin/remote-branch-2'] : []
     })
@@ -411,7 +433,7 @@ describe('git-directory-helper tests', () => {
     // Arrange
     await setup(removesDescendantRemoteBranches)
     await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
-    const mockBranchList = git.branchList as jest.Mock<any, any>
+    const mockBranchList = git.branchList as jest.Mock<any>
     mockBranchList.mockImplementation(async (remote: boolean) => {
       return remote
         ? ['origin/remote-branch-1/conflict', 'origin/remote-branch-2']
@@ -507,5 +529,5 @@ async function setup(testName: string): Promise<void> {
       return true
     }),
     version: jest.fn()
-  }
+  } as unknown as IGitCommandManager
 }

__test__/git-version.test.ts

@@ -1,5 +1,6 @@
-import {GitVersion} from '../src/git-version'
-import {MinimumGitSparseCheckoutVersion} from '../src/git-command-manager'
+import {describe, it, expect} from '@jest/globals'
+import {GitVersion} from '../src/git-version.js'
+import {MinimumGitSparseCheckoutVersion} from '../src/git-command-manager.js'
 
 describe('git-version tests', () => {
   it('basics', async () => {

__test__/github-api-helper.test.ts

@@ -1,11 +1,25 @@
-import * as core from '@actions/core'
-import * as github from '@actions/github'
-import * as githubApiHelper from '../lib/github-api-helper'
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals'
+
+// Mock @actions/core
+const mockDebug = jest.fn()
+jest.unstable_mockModule('@actions/core', () => ({
+  debug: mockDebug,
+  info: jest.fn(),
+  warning: jest.fn(),
+  error: jest.fn()
+}))
+
+// Mock @actions/github
+const mockGetOctokit = jest.fn()
+jest.unstable_mockModule('@actions/github', () => ({
+  getOctokit: mockGetOctokit
+}))
+
+// Dynamic imports after mocking
+const githubApiHelper = await import('../src/github-api-helper.js')
 
 describe('github-api-helper object format', () => {
-  let getOctokitSpy: jest.SpyInstance
-  let debugSpy: jest.SpyInstance
-  let request: jest.Mock
+  let request: jest.Mock<any>
 
   function mockHashAlgorithmApi(hashAlgorithm: string): void {
     request = jest.fn(async () => ({
@@ -13,17 +27,18 @@ describe('github-api-helper object format', () => {
         hash_algorithm: hashAlgorithm
       }
     }))
-    getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+    mockGetOctokit.mockReturnValue({
       request
     } as any)
   }
 
   beforeEach(() => {
-    debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+    mockDebug.mockClear()
+    mockGetOctokit.mockClear()
   })
 
   afterEach(() => {
-    jest.restoreAllMocks()
+    jest.clearAllMocks()
   })
 
   it('detects SHA-256 from the repository hash algorithm endpoint', async () => {
@@ -33,7 +48,7 @@ describe('github-api-helper object format', () => {
       githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
     ).resolves.toEqual({format: 'sha256', succeeded: true})
 
-    expect(getOctokitSpy).toHaveBeenCalledWith(
+    expect(mockGetOctokit).toHaveBeenCalledWith(
       'token',
       expect.objectContaining({baseUrl: 'https://api.github.com'})
     )
@@ -54,7 +69,6 @@ describe('github-api-helper object format', () => {
   it('detects object format from an existing commit without API calls', async () => {
     const commitSha =
       '9422233ca7ee1b17f1e905d0e141faf0c401556c41cdc6acd71c6bd685da2e92'
-    getOctokitSpy = jest.spyOn(github, 'getOctokit')
 
     await expect(
       githubApiHelper.tryGetRepositoryObjectFormat(
@@ -66,7 +80,7 @@ describe('github-api-helper object format', () => {
       )
     ).resolves.toEqual({format: 'sha256', succeeded: true})
 
-    expect(getOctokitSpy).not.toHaveBeenCalled()
+    expect(mockGetOctokit).not.toHaveBeenCalled()
   })
 
   it('returns unsuccessful when the hash algorithm endpoint value is not recognized', async () => {
@@ -75,7 +89,7 @@ describe('github-api-helper object format', () => {
     await expect(
       githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
     ).resolves.toEqual({format: '', succeeded: false})
-    expect(debugSpy).toHaveBeenCalledWith(
+    expect(mockDebug).toHaveBeenCalledWith(
       'Unable to determine repository object format from hash-algorithm endpoint'
     )
   })
@@ -84,14 +98,14 @@ describe('github-api-helper object format', () => {
     request = jest.fn(async () => {
       throw new Error('not found')
     })
-    jest.spyOn(github, 'getOctokit').mockReturnValue({
+    mockGetOctokit.mockReturnValue({
       request
     } as any)
 
     await expect(
       githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
     ).resolves.toEqual({format: '', succeeded: false})
-    expect(debugSpy).toHaveBeenCalledWith(
+    expect(mockDebug).toHaveBeenCalledWith(
       'Unable to determine repository object format from hash-algorithm endpoint: not found'
     )
   })

__test__/input-helper.test.ts

@@ -1,10 +1,13 @@
-import * as core from '@actions/core'
-import * as fsHelper from '../lib/fs-helper'
-import * as github from '@actions/github'
-import * as inputHelper from '../lib/input-helper'
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  beforeEach,
+  afterAll
+} from '@jest/globals'
 import * as path from 'path'
-import * as workflowContextHelper from '../lib/workflow-context-helper'
-import {IGitSourceSettings} from '../lib/git-source-settings'
 
 const originalGitHubWorkspace = process.env['GITHUB_WORKSPACE']
 const gitHubWorkspace = path.resolve('/checkout-tests/workspace')
@@ -12,42 +15,58 @@ const gitHubWorkspace = path.resolve('/checkout-tests/workspace')
 // Inputs for mock @actions/core
 let inputs = {} as any
 
-// Shallow clone original @actions/github context
-let originalContext = {...github.context}
+// Mutable mock github context
+const mockGithubContext: any = {
+  ref: 'refs/heads/some-ref',
+  sha: '1234567890123456789012345678901234567890',
+  repo: {owner: 'some-owner', repo: 'some-repo'},
+  eventName: '',
+  payload: {}
+}
+
+// Mock @actions/core before loading input-helper
+jest.unstable_mockModule('@actions/core', () => ({
+  getInput: jest.fn((name: string) => inputs[name]),
+  getBooleanInput: jest.fn((name: string) => inputs[name]),
+  getMultilineInput: jest.fn((name: string) =>
+    inputs[name] ? String(inputs[name]).split('\n').filter(Boolean) : []
+  ),
+  error: jest.fn(),
+  warning: jest.fn(),
+  info: jest.fn(),
+  debug: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  setSecret: jest.fn()
+}))
+
+// Mock @actions/github before loading input-helper
+jest.unstable_mockModule('@actions/github', () => ({
+  context: mockGithubContext,
+  getOctokit: jest.fn()
+}))
+
+// Mock fs-helper
+const mockDirectoryExistsSync = jest.fn((p: string) => p === gitHubWorkspace)
+jest.unstable_mockModule('../src/fs-helper.js', () => ({
+  directoryExistsSync: mockDirectoryExistsSync,
+  fileExistsSync: jest.fn()
+}))
+
+// Mock workflow-context-helper
+const mockGetOrganizationId = jest.fn(async () => 123456)
+jest.unstable_mockModule('../src/workflow-context-helper.js', () => ({
+  getOrganizationId: mockGetOrganizationId
+}))
+
+// Dynamic imports after mocking
+const core = await import('@actions/core')
+const inputHelper = await import('../src/input-helper.js')
+type IGitSourceSettings =
+  import('../src/git-source-settings.js').IGitSourceSettings
 
 describe('input-helper tests', () => {
   beforeAll(() => {
-    // Mock getInput
-    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
-      return inputs[name]
-    })
-
-    // Mock error/warning/info/debug
-    jest.spyOn(core, 'error').mockImplementation(jest.fn())
-    jest.spyOn(core, 'warning').mockImplementation(jest.fn())
-    jest.spyOn(core, 'info').mockImplementation(jest.fn())
-    jest.spyOn(core, 'debug').mockImplementation(jest.fn())
-
-    // Mock github context
-    jest.spyOn(github.context, 'repo', 'get').mockImplementation(() => {
-      return {
-        owner: 'some-owner',
-        repo: 'some-repo'
-      }
-    })
-    github.context.ref = 'refs/heads/some-ref'
-    github.context.sha = '1234567890123456789012345678901234567890'
-
-    // Mock ./fs-helper directoryExistsSync()
-    jest
-      .spyOn(fsHelper, 'directoryExistsSync')
-      .mockImplementation((path: string) => path == gitHubWorkspace)
-
-    // Mock ./workflowContextHelper getOrganizationId()
-    jest
-      .spyOn(workflowContextHelper, 'getOrganizationId')
-      .mockImplementation(() => Promise.resolve(123456))
-
     // GitHub workspace
     process.env['GITHUB_WORKSPACE'] = gitHubWorkspace
   })
@@ -55,6 +74,15 @@ describe('input-helper tests', () => {
   beforeEach(() => {
     // Reset inputs
     inputs = {}
+    jest.clearAllMocks()
+    // Re-apply default mocks
+    ;(core.getInput as jest.Mock<any>).mockImplementation(
+      (name: string) => inputs[name]
+    )
+    mockDirectoryExistsSync.mockImplementation(
+      (p: string) => p === gitHubWorkspace
+    )
+    mockGetOrganizationId.mockResolvedValue(123456)
   })
 
   afterAll(() => {
@@ -65,11 +93,8 @@ describe('input-helper tests', () => {
     }
 
     // Restore @actions/github context
-    github.context.ref = originalContext.ref
-    github.context.sha = originalContext.sha
-
-    // Restore
-    jest.restoreAllMocks()
+    mockGithubContext.ref = 'refs/heads/some-ref'
+    mockGithubContext.sha = '1234567890123456789012345678901234567890'
   })
 
   it('sets defaults', async () => {
@@ -91,18 +116,19 @@ describe('input-helper tests', () => {
     expect(settings.repositoryOwner).toBe('some-owner')
     expect(settings.repositoryPath).toBe(gitHubWorkspace)
     expect(settings.setSafeDirectory).toBe(true)
+    expect(settings.allowUnsafePrCheckout).toBe(false)
   })
 
   it('qualifies ref', async () => {
-    let originalRef = github.context.ref
+    let originalRef = mockGithubContext.ref
     try {
-      github.context.ref = 'some-unqualified-ref'
+      mockGithubContext.ref = 'some-unqualified-ref'
       const settings: IGitSourceSettings = await inputHelper.getInputs()
       expect(settings).toBeTruthy()
       expect(settings.commit).toBe('1234567890123456789012345678901234567890')
       expect(settings.ref).toBe('refs/heads/some-unqualified-ref')
     } finally {
-      github.context.ref = originalRef
+      mockGithubContext.ref = originalRef
     }
   })
 

__test__/ref-helper.test.ts

@@ -1,8 +1,36 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals'
 import * as assert from 'assert'
-import * as core from '@actions/core'
-import * as github from '@actions/github'
-import * as refHelper from '../lib/ref-helper'
-import {IGitCommandManager} from '../lib/git-command-manager'
+
+// Mutable mock github context
+const mockGithubContext: any = {
+  eventName: '',
+  payload: {},
+  repo: {owner: 'some-owner', repo: 'some-repo'},
+  ref: '',
+  sha: ''
+}
+
+// Mock @actions/core
+const mockDebug = jest.fn()
+jest.unstable_mockModule('@actions/core', () => ({
+  debug: mockDebug,
+  info: jest.fn(),
+  warning: jest.fn(),
+  error: jest.fn(),
+  setFailed: jest.fn()
+}))
+
+// Mock @actions/github
+const mockGetOctokit = jest.fn()
+jest.unstable_mockModule('@actions/github', () => ({
+  context: mockGithubContext,
+  getOctokit: mockGetOctokit
+}))
+
+// Dynamic imports after mocking
+const refHelper = await import('../src/ref-helper.js')
+type IGitCommandManager =
+  import('../src/git-command-manager.js').IGitCommandManager
 
 const commit = '1234567890123456789012345678901234567890'
 const sha256Commit =
@@ -12,6 +40,7 @@ let git: IGitCommandManager
 describe('ref-helper tests', () => {
   beforeEach(() => {
     git = {} as unknown as IGitCommandManager
+    jest.clearAllMocks()
   })
 
   it('getCheckoutInfo requires git', async () => {
@@ -166,14 +195,12 @@ describe('ref-helper tests', () => {
   })
 
   it('getRefSpec sha + refs/tags/ with fetchTags', async () => {
-    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
     const refSpec = refHelper.getRefSpec('refs/tags/my-tag', commit, true)
     expect(refSpec.length).toBe(1)
     expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
   })
 
   it('getRefSpec sha + refs/heads/ with fetchTags', async () => {
-    // When fetchTags is true, include both the branch refspec and tags wildcard
     const refSpec = refHelper.getRefSpec('refs/heads/my/branch', commit, true)
     expect(refSpec.length).toBe(2)
     expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
@@ -194,7 +221,6 @@ describe('ref-helper tests', () => {
   })
 
   it('getRefSpec unqualified ref only with fetchTags', async () => {
-    // When fetchTags is true, skip specific tag pattern since wildcard covers all
     const refSpec = refHelper.getRefSpec('my-ref', '', true)
     expect(refSpec.length).toBe(2)
     expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
@@ -222,14 +248,12 @@ describe('ref-helper tests', () => {
   })
 
   it('getRefSpec refs/tags/ only with fetchTags', async () => {
-    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
     const refSpec = refHelper.getRefSpec('refs/tags/my-tag', '', true)
     expect(refSpec.length).toBe(1)
     expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
   })
 
   it('getRefSpec refs/heads/ only with fetchTags', async () => {
-    // When fetchTags is true, include both the branch refspec and tags wildcard
     const refSpec = refHelper.getRefSpec('refs/heads/my/branch', '', true)
     expect(refSpec.length).toBe(2)
     expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
@@ -248,9 +272,7 @@ describe('ref-helper tests', () => {
       '1111111111222222222233333333334444444444555555555566666666667777'
     const sha256Base =
       'aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeeeffffffffff0000'
-    let debugSpy: jest.SpyInstance
-    let getOctokitSpy: jest.SpyInstance
-    let repoGetSpy: jest.Mock
+    let repoGetSpy: jest.Mock<any>
     let originalEventName: string
     let originalPayload: unknown
     let originalRef: string
@@ -261,10 +283,10 @@ describe('ref-helper tests', () => {
       expectedBaseSha: string,
       mergeCommit: string
     ): void {
-      ;(github.context as any).eventName = 'pull_request'
-      github.context.ref = ref
-      github.context.sha = mergeCommit
-      ;(github.context as any).payload = {
+      mockGithubContext.eventName = 'pull_request'
+      mockGithubContext.ref = ref
+      mockGithubContext.sha = mergeCommit
+      mockGithubContext.payload = {
         action: 'synchronize',
         after: expectedHeadSha,
         number: 123,
@@ -280,18 +302,18 @@ describe('ref-helper tests', () => {
     }
 
     beforeEach(() => {
-      originalEventName = github.context.eventName
-      originalPayload = github.context.payload
-      originalRef = github.context.ref
-      originalSha = github.context.sha
+      originalEventName = mockGithubContext.eventName
+      originalPayload = mockGithubContext.payload
+      originalRef = mockGithubContext.ref
+      originalSha = mockGithubContext.sha
 
-      jest.spyOn(github.context, 'repo', 'get').mockReturnValue({
+      mockGithubContext.repo = {
         owner: repositoryOwner,
         repo: repositoryName
-      })
-      debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+      }
+
       repoGetSpy = jest.fn(async () => ({}))
-      getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+      mockGetOctokit.mockReturnValue({
         rest: {
           repos: {
             get: repoGetSpy
@@ -301,11 +323,11 @@ describe('ref-helper tests', () => {
     })
 
     afterEach(() => {
-      ;(github.context as any).eventName = originalEventName
-      ;(github.context as any).payload = originalPayload
-      github.context.ref = originalRef
-      github.context.sha = originalSha
-      jest.restoreAllMocks()
+      mockGithubContext.eventName = originalEventName
+      mockGithubContext.payload = originalPayload
+      mockGithubContext.ref = originalRef
+      mockGithubContext.sha = originalSha
+      jest.clearAllMocks()
     })
 
     it('returns early for SHA-1 merge commit', async () => {
@@ -320,7 +342,7 @@ describe('ref-helper tests', () => {
         commit
       )
 
-      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(mockGetOctokit).not.toHaveBeenCalled()
       expect(repoGetSpy).not.toHaveBeenCalled()
     })
 
@@ -338,7 +360,7 @@ describe('ref-helper tests', () => {
         sha256Commit
       )
 
-      expect(getOctokitSpy).toHaveBeenCalledWith(
+      expect(mockGetOctokit).toHaveBeenCalledWith(
         'token',
         expect.objectContaining({
           userAgent: expect.stringContaining(
@@ -350,10 +372,10 @@ describe('ref-helper tests', () => {
         owner: repositoryOwner,
         repo: repositoryName
       })
-      expect(debugSpy).toHaveBeenCalledWith(
+      expect(mockDebug).toHaveBeenCalledWith(
         `Expected head sha ${sha256Head}; actual head sha ${actualHeadSha}`
       )
-      expect(debugSpy).not.toHaveBeenCalledWith('Unexpected message format')
+      expect(mockDebug).not.toHaveBeenCalledWith('Unexpected message format')
     })
 
     it('does not match 50-char hex as a valid merge', async () => {
@@ -370,9 +392,9 @@ describe('ref-helper tests', () => {
         commit
       )
 
-      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(mockGetOctokit).not.toHaveBeenCalled()
       expect(repoGetSpy).not.toHaveBeenCalled()
-      expect(debugSpy).toHaveBeenCalledWith('Unexpected message format')
+      expect(mockDebug).toHaveBeenCalledWith('Unexpected message format')
     })
   })
 })

__test__/retry-helper.test.ts

@@ -1,16 +1,32 @@
-import * as core from '@actions/core'
-import {RetryHelper} from '../lib/retry-helper'
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  beforeEach,
+  afterAll
+} from '@jest/globals'
+
+let info: string[] = []
+
+// Mock @actions/core before loading retry-helper
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn((message: string) => {
+    info.push(message)
+  }),
+  debug: jest.fn(),
+  warning: jest.fn(),
+  error: jest.fn()
+}))
+
+// Dynamic imports after mocking
+const {RetryHelper} = await import('../src/retry-helper.js')
 
-let info: string[]
 let retryHelper: any
 
 describe('retry-helper tests', () => {
   beforeAll(() => {
-    // Mock @actions/core info()
-    jest.spyOn(core, 'info').mockImplementation((message: string) => {
-      info.push(message)
-    })
-
     retryHelper = new RetryHelper(3, 0, 0)
   })
 
@@ -20,7 +36,6 @@ describe('retry-helper tests', () => {
   })
 
   afterAll(() => {
-    // Restore
     jest.restoreAllMocks()
   })
 

__test__/unsafe-pr-checkout-helper.test.ts

@@ -0,0 +1,284 @@
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  beforeAll,
+  afterEach,
+  afterAll
+} from '@jest/globals'
+
+const BASE_REPO_ID = 100
+const FORK_REPO_ID = 200
+const PR_HEAD_SHA = '1111111111111111111111111111111111111111'
+const PR_MERGE_SHA = '2222222222222222222222222222222222222222'
+const SAFE_BASE_SHA = '3333333333333333333333333333333333333333'
+const WORKFLOW_RUN_HEAD_COMMIT_SHA = '4444444444444444444444444444444444444444'
+const BASE_QUALIFIED_REPO = 'some-owner/some-repo'
+const FORK_QUALIFIED_REPO = 'another-repo/fork'
+
+// Mutable mock context
+const mockContext: any = {
+  eventName: '',
+  payload: {},
+  repo: {owner: 'some-owner', repo: 'some-repo'},
+  ref: '',
+  sha: ''
+}
+
+jest.unstable_mockModule('@actions/github', () => ({
+  context: mockContext
+}))
+
+// Dynamic imports after mocking
+const {assertSafePrCheckout} =
+  await import('../src/unsafe-pr-checkout-helper.js')
+
+const originalEventName = mockContext.eventName
+const originalPayload = mockContext.payload
+
+function setContext(eventName: string, payload: object): void {
+  mockContext.eventName = eventName
+  mockContext.payload = payload
+}
+
+function forkPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: FORK_REPO_ID, full_name: FORK_QUALIFIED_REPO}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function sameRepoPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: BASE_REPO_ID, full_name: BASE_QUALIFIED_REPO}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function forkWorkflowRunPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    workflow_run: {
+      event: 'pull_request',
+      head_commit: {id: WORKFLOW_RUN_HEAD_COMMIT_SHA},
+      head_repository: {id: FORK_REPO_ID, full_name: FORK_QUALIFIED_REPO}
+    }
+  }
+}
+
+describe('unsafe-pr-checkout-helper', () => {
+  beforeAll(() => {
+    mockContext.repo = {owner: 'some-owner', repo: 'some-repo'}
+  })
+
+  afterEach(() => {
+    mockContext.eventName = originalEventName
+    mockContext.payload = originalPayload
+  })
+
+  afterAll(() => {
+    mockContext.eventName = originalEventName
+    mockContext.payload = originalPayload
+  })
+
+  it('allows pull_request events untouched', () => {
+    setContext('pull_request', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'attacker/fork',
+        ref: 'refs/pull/1/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows pull_request_target default checkout (base branch)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/heads/main',
+        commit: SAFE_BASE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows same-repo pull_request_target checkout of PR head', () => {
+    setContext('pull_request_target', sameRepoPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses pull_request_target fork PR head SHA checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/Refusing to check out fork pull request code/)
+  })
+
+  it('refuses pull_request_target fork PR merge_commit_sha checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_MERGE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/allow-unsafe-pr-checkout/)
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (head)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/head',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (merge)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target when repository points at the fork', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: FORK_QUALIFIED_REPO,
+        ref: 'refs/heads/main',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows pull_request_target checkout of an unrelated third-party repo', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'some-other/unrelated',
+        ref: 'refs/heads/main',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses pull_request_target ignoring repository case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: FORK_QUALIFIED_REPO.toUpperCase(),
+        ref: '',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target ignoring commit SHA case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA.toUpperCase(),
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows pull_request_target fork PR checkout when opted in', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: true
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses workflow_run fork PR head_commit.id checkout', () => {
+    setContext('workflow_run', forkWorkflowRunPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses workflow_run with pull_request_target underlying event', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {event: string}
+    }
+    payload.workflow_run.event = 'pull_request_target'
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows workflow_run same-repo PR (head_repository.id matches base)', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {head_repository: {id: number}}
+    }
+    payload.workflow_run.head_repository.id = BASE_REPO_ID
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+})

__test__/url-helper.test.ts

@@ -1,4 +1,5 @@
-import * as urlHelper from '../src/url-helper'
+import {jest, describe, it, expect, beforeEach, afterAll} from '@jest/globals'
+import * as urlHelper from '../src/url-helper.js'
 
 describe('getServerUrl tests', () => {
   it('basics', async () => {

action.yml

@@ -98,6 +98,15 @@ inputs:
   github-server-url:
     description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Example URLs are https://github.com or https://my-ghes-server.example.com
     required: false
+  allow-unsafe-pr-checkout:
+    description: >
+      Required to check out fork pull request code from a workflow triggered by
+      `pull_request_target` or `workflow_run`. These workflows run with the
+      base repository's GITHUB_TOKEN, secrets, default-branch cache scope, and
+      runner access; fetching and executing a fork's code in that trusted
+      context commonly leads to "pwn request" vulnerabilities. Set to `true`
+      only after reviewing the risks at https://gh.io/securely-using-pull_request_target.
+    default: false
 outputs:
   ref:
     description: 'The branch, tag or SHA that was checked out'

dist/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

jest.config.js

@@ -1,12 +0,0 @@
-module.exports = {
-  clearMocks: true,
-  fakeTimers: {},
-  moduleFileExtensions: ['js', 'ts'],
-  testEnvironment: 'node',
-  testMatch: ['**/*.test.ts'],
-  testRunner: 'jest-circus/runner',
-  transform: {
-    '^.+\\.ts$': 'ts-jest'
-  },
-  verbose: true
-}

jest.config.ts

@@ -0,0 +1,24 @@
+export default {
+  clearMocks: true,
+  moduleFileExtensions: ['js', 'ts'],
+  roots: ['<rootDir>'],
+  testEnvironment: 'node',
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': [
+      'ts-jest',
+      {
+        useESM: true,
+        diagnostics: {
+          ignoreCodes: [151002]
+        }
+      }
+    ]
+  },
+  extensionsToTreatAsEsm: ['.ts'],
+  transformIgnorePatterns: ['node_modules/(?!(@actions)/)'],
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1'
+  },
+  verbose: true
+}

package.json

@@ -1,14 +1,15 @@
 {
   "name": "checkout",
-  "version": "5.0.0",
+  "version": "7.0.0",
   "description": "checkout action",
+  "type": "module",
   "main": "lib/main.js",
   "scripts": {
-    "build": "tsc && ncc build && node lib/misc/generate-docs.js",
+    "build": "tsc && ncc build src/main.ts -o dist && node lib/misc/generate-docs.js",
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
     "lint": "eslint src/**/*.ts",
-    "test": "jest",
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
     "licensed-check": "src/misc/licensed-check.sh",
     "licensed-generate": "src/misc/licensed-generate.sh"
   },
@@ -27,29 +28,30 @@
     "url": "https://github.com/actions/checkout/issues"
   },
   "homepage": "https://github.com/actions/checkout#readme",
+  "engines": {
+    "node": ">=24"
+  },
   "dependencies": {
-    "@actions/core": "^1.10.1",
-    "@actions/exec": "^1.1.1",
-    "@actions/github": "^6.0.0",
-    "@actions/io": "^1.1.3",
-    "@actions/tool-cache": "^2.0.1",
-    "uuid": "^9.0.1"
+    "@actions/core": "^3.0.1",
+    "@actions/exec": "^3.0.0",
+    "@actions/github": "^9.1.1",
+    "@actions/io": "^3.0.2",
+    "@actions/tool-cache": "^4.0.0"
   },
   "devDependencies": {
     "@types/jest": "^29.5.12",
     "@types/node": "^24.1.0",
-    "@types/uuid": "^9.0.8",
     "@typescript-eslint/eslint-plugin": "^7.9.0",
     "@typescript-eslint/parser": "^7.9.0",
-    "@vercel/ncc": "^0.38.1",
+    "@vercel/ncc": "^0.44.0",
     "eslint": "^8.57.0",
     "eslint-plugin-github": "^4.10.2",
     "eslint-plugin-jest": "^28.8.2",
     "jest": "^29.7.0",
-    "jest-circus": "^29.7.0",
-    "js-yaml": "^4.1.0",
-    "prettier": "^3.3.3",
-    "ts-jest": "^29.2.5",
+    "js-yaml": "^4.2.0",
+    "prettier": "^3.8.4",
+    "ts-jest": "^29.4.11",
+    "ts-node": "^10.9.2",
     "typescript": "^5.5.4"
   }
 }

src/git-auth-helper.ts

@@ -5,12 +5,12 @@ import * as fs from 'fs'
 import * as io from '@actions/io'
 import * as os from 'os'
 import * as path from 'path'
-import * as regexpHelper from './regexp-helper'
-import * as stateHelper from './state-helper'
-import * as urlHelper from './url-helper'
-import {v4 as uuid} from 'uuid'
-import {IGitCommandManager} from './git-command-manager'
-import {IGitSourceSettings} from './git-source-settings'
+import * as regexpHelper from './regexp-helper.js'
+import * as stateHelper from './state-helper.js'
+import * as urlHelper from './url-helper.js'
+import {randomUUID} from 'crypto'
+import {IGitCommandManager} from './git-command-manager.js'
+import {IGitSourceSettings} from './git-source-settings.js'
 
 const IS_WINDOWS = process.platform === 'win32'
 const SSH_COMMAND_KEY = 'core.sshCommand'
@@ -90,7 +90,7 @@ class GitAuthHelper {
     // Create a temp home directory
     const runnerTemp = process.env['RUNNER_TEMP'] || ''
     assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
-    const uniqueId = uuid()
+    const uniqueId = randomUUID()
     this.temporaryHomePath = path.join(runnerTemp, uniqueId)
     await fs.promises.mkdir(this.temporaryHomePath, {recursive: true})
 
@@ -255,7 +255,7 @@ class GitAuthHelper {
     // Write key
     const runnerTemp = process.env['RUNNER_TEMP'] || ''
     assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
-    const uniqueId = uuid()
+    const uniqueId = randomUUID()
     this.sshKeyPath = path.join(runnerTemp, uniqueId)
     stateHelper.setSshKeyPath(this.sshKeyPath)
     await fs.promises.mkdir(runnerTemp, {recursive: true})
@@ -422,7 +422,7 @@ class GitAuthHelper {
     assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
 
     // Create a unique filename for this checkout instance
-    const configFileName = `git-credentials-${uuid()}.config`
+    const configFileName = `git-credentials-${randomUUID()}.config`
     this.credentialsConfigPath = path.join(runnerTemp, configFileName)
 
     core.debug(`Credentials config path: ${this.credentialsConfigPath}`)

src/git-command-manager.ts

@@ -1,13 +1,13 @@
 import * as core from '@actions/core'
 import * as exec from '@actions/exec'
 import * as fs from 'fs'
-import * as fshelper from './fs-helper'
+import * as fshelper from './fs-helper.js'
 import * as io from '@actions/io'
 import * as path from 'path'
-import * as refHelper from './ref-helper'
-import * as regexpHelper from './regexp-helper'
-import * as retryHelper from './retry-helper'
-import {GitVersion} from './git-version'
+import * as refHelper from './ref-helper.js'
+import * as regexpHelper from './regexp-helper.js'
+import * as retryHelper from './retry-helper.js'
+import {GitVersion} from './git-version.js'
 
 // Auth header not supported before 2.9
 // Wire protocol v2 not supported before 2.18

src/git-directory-helper.ts

@@ -1,10 +1,10 @@
 import * as assert from 'assert'
 import * as core from '@actions/core'
 import * as fs from 'fs'
-import * as fsHelper from './fs-helper'
+import * as fsHelper from './fs-helper.js'
 import * as io from '@actions/io'
 import * as path from 'path'
-import {IGitCommandManager} from './git-command-manager'
+import {IGitCommandManager} from './git-command-manager.js'
 
 export async function prepareExistingDirectory(
   git: IGitCommandManager | undefined,

src/git-source-provider.ts

@@ -1,19 +1,19 @@
 import * as core from '@actions/core'
-import * as fsHelper from './fs-helper'
-import * as gitAuthHelper from './git-auth-helper'
-import * as gitCommandManager from './git-command-manager'
-import * as gitDirectoryHelper from './git-directory-helper'
-import * as githubApiHelper from './github-api-helper'
+import * as fsHelper from './fs-helper.js'
+import * as gitAuthHelper from './git-auth-helper.js'
+import * as gitCommandManager from './git-command-manager.js'
+import * as gitDirectoryHelper from './git-directory-helper.js'
+import * as githubApiHelper from './github-api-helper.js'
 import * as io from '@actions/io'
 import * as path from 'path'
-import * as refHelper from './ref-helper'
-import * as stateHelper from './state-helper'
-import * as urlHelper from './url-helper'
+import * as refHelper from './ref-helper.js'
+import * as stateHelper from './state-helper.js'
+import * as urlHelper from './url-helper.js'
 import {
   MinimumGitSparseCheckoutVersion,
   IGitCommandManager
-} from './git-command-manager'
-import {IGitSourceSettings} from './git-source-settings'
+} from './git-command-manager.js'
+import {IGitSourceSettings} from './git-source-settings.js'
 
 export async function getSource(settings: IGitSourceSettings): Promise<void> {
   // Repository URL

src/git-source-settings.ts

@@ -118,4 +118,10 @@ export interface IGitSourceSettings {
    * User override on the GitHub Server/Host URL that hosts the repository to be cloned
    */
   githubServerUrl: string | undefined
+
+  /**
+   * Opt-in to allow checking out fork pull request code from a workflow
+   * triggered by pull_request_target or workflow_run.
+   */
+  allowUnsafePrCheckout: boolean
 }

src/github-api-helper.ts

@@ -4,10 +4,10 @@ import * as fs from 'fs'
 import * as github from '@actions/github'
 import * as io from '@actions/io'
 import * as path from 'path'
-import * as retryHelper from './retry-helper'
+import * as retryHelper from './retry-helper.js'
 import * as toolCache from '@actions/tool-cache'
-import {v4 as uuid} from 'uuid'
-import {getServerApiUrl} from './url-helper'
+import {randomUUID} from 'crypto'
+import {getServerApiUrl} from './url-helper.js'
 
 const IS_WINDOWS = process.platform === 'win32'
 
@@ -39,7 +39,7 @@ export async function downloadRepository(
 
   // Write archive to disk
   core.info('Writing archive to disk')
-  const uniqueId = uuid()
+  const uniqueId = randomUUID()
   const archivePath = IS_WINDOWS
     ? path.join(repositoryPath, `${uniqueId}.zip`)
     : path.join(repositoryPath, `${uniqueId}.tar.gz`)

src/input-helper.ts

@@ -1,9 +1,10 @@
 import * as core from '@actions/core'
-import * as fsHelper from './fs-helper'
+import * as fsHelper from './fs-helper.js'
 import * as github from '@actions/github'
 import * as path from 'path'
-import * as workflowContextHelper from './workflow-context-helper'
-import {IGitSourceSettings} from './git-source-settings'
+import * as unsafePrCheckoutHelper from './unsafe-pr-checkout-helper.js'
+import * as workflowContextHelper from './workflow-context-helper.js'
+import {IGitSourceSettings} from './git-source-settings.js'
 
 export async function getInputs(): Promise<IGitSourceSettings> {
   const result = {} as unknown as IGitSourceSettings
@@ -161,5 +162,18 @@ export async function getInputs(): Promise<IGitSourceSettings> {
   result.githubServerUrl = core.getInput('github-server-url')
   core.debug(`GitHub Host URL = ${result.githubServerUrl}`)
 
+  // Allow unsafe PR checkout (opt-in for pull_request_target / workflow_run fork PRs)
+  result.allowUnsafePrCheckout =
+    (core.getInput('allow-unsafe-pr-checkout') || 'false').toUpperCase() ===
+    'TRUE'
+  core.debug(`allow unsafe PR checkout = ${result.allowUnsafePrCheckout}`)
+
+  unsafePrCheckoutHelper.assertSafePrCheckout({
+    qualifiedRepository,
+    ref: result.ref,
+    commit: result.commit,
+    allowUnsafePrCheckout: result.allowUnsafePrCheckout
+  })
+
   return result
 }

src/main.ts

@@ -1,9 +1,11 @@
 import * as core from '@actions/core'
-import * as coreCommand from '@actions/core/lib/command'
-import * as gitSourceProvider from './git-source-provider'
-import * as inputHelper from './input-helper'
+import * as gitSourceProvider from './git-source-provider.js'
+import * as inputHelper from './input-helper.js'
 import * as path from 'path'
-import * as stateHelper from './state-helper'
+import * as stateHelper from './state-helper.js'
+import {fileURLToPath} from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 async function run(): Promise<void> {
   try {
@@ -11,10 +13,8 @@ async function run(): Promise<void> {
 
     try {
       // Register problem matcher
-      coreCommand.issueCommand(
-        'add-matcher',
-        {},
-        path.join(__dirname, 'problem-matcher.json')
+      core.info(
+        `::add-matcher::${path.join(__dirname, 'problem-matcher.json')}`
       )
 
       // Get sources
@@ -22,7 +22,7 @@ async function run(): Promise<void> {
       core.setOutput('ref', sourceSettings.ref)
     } finally {
       // Unregister problem matcher
-      coreCommand.issueCommand('remove-matcher', {owner: 'checkout-git'}, '')
+      core.info('::remove-matcher owner=checkout-git::')
     }
   } catch (error) {
     core.setFailed(`${(error as any)?.message ?? error}`)

src/misc/generate-docs.ts

@@ -2,6 +2,9 @@ import * as fs from 'fs'
 import * as os from 'os'
 import * as path from 'path'
 import * as yaml from 'js-yaml'
+import {fileURLToPath} from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 //
 // SUMMARY
@@ -120,7 +123,7 @@ function updateUsage(
 }
 
 updateUsage(
-  'actions/checkout@v6',
+  'actions/checkout@v7',
   path.join(__dirname, '..', '..', 'action.yml'),
   path.join(__dirname, '..', '..', 'README.md')
 )

src/ref-helper.ts

@@ -1,7 +1,7 @@
-import {IGitCommandManager} from './git-command-manager'
+import {IGitCommandManager} from './git-command-manager.js'
 import * as core from '@actions/core'
 import * as github from '@actions/github'
-import {getServerApiUrl, isGhes} from './url-helper'
+import {getServerApiUrl, isGhes} from './url-helper.js'
 
 export const tagsRefSpec = '+refs/tags/*:refs/tags/*'
 
@@ -292,7 +292,7 @@ export async function checkCommitInfo(
   }
 }
 
-function fromPayload(path: string): any {
+export function fromPayload(path: string): any {
   return select(github.context.payload, path)
 }
 

src/unsafe-pr-checkout-helper.ts

@@ -0,0 +1,88 @@
+import * as github from '@actions/github'
+import {fromPayload} from './ref-helper.js'
+
+const PR_REF_PATTERN = /^refs\/pull\/[0-9]+\/(?:head|merge)$/
+
+export interface IUnsafePrCheckoutInput {
+  qualifiedRepository: string
+  ref: string
+  commit: string | undefined
+  allowUnsafePrCheckout: boolean
+}
+
+export function assertSafePrCheckout(input: IUnsafePrCheckoutInput): void {
+  if (input.allowUnsafePrCheckout) {
+    return
+  }
+
+  const eventName = github.context.eventName
+  if (eventName !== 'pull_request_target' && eventName !== 'workflow_run') {
+    return
+  }
+
+  const baseRepoId = fromPayload('repository.id')
+  if (typeof baseRepoId !== 'number') {
+    return
+  }
+
+  let prHeadRepoId: unknown
+  let prHeadRepoFullName: unknown
+  const prShas: string[] = []
+
+  if (eventName === 'pull_request_target') {
+    prHeadRepoId = fromPayload('pull_request.head.repo.id')
+    prHeadRepoFullName = fromPayload('pull_request.head.repo.full_name')
+    pushIfSha(prShas, fromPayload('pull_request.head.sha'))
+    pushIfSha(prShas, fromPayload('pull_request.merge_commit_sha'))
+  } else {
+    const wrEvent = fromPayload('workflow_run.event')
+    if (typeof wrEvent !== 'string' || !wrEvent.startsWith('pull_request')) {
+      return
+    }
+    prHeadRepoId = fromPayload('workflow_run.head_repository.id')
+    prHeadRepoFullName = fromPayload('workflow_run.head_repository.full_name')
+    pushIfSha(prShas, fromPayload('workflow_run.head_commit.id'))
+    // For `pull_request_target`-triggered workflow_run, `head_sha` is the base
+    // default branch SHA (not the PR head)
+    if (wrEvent !== 'pull_request_target') {
+      pushIfSha(prShas, fromPayload('workflow_run.head_sha'))
+    }
+  }
+
+  // (A) Fork PR?
+  if (typeof prHeadRepoId !== 'number' || prHeadRepoId === baseRepoId) {
+    return
+  }
+
+  // (B) We cannot check for all fork PR refs so check to see
+  // if the resolved input points to the fork PR sha we have in the payload
+  const repositoryMatchesPrHead =
+    typeof prHeadRepoFullName === 'string' &&
+    input.qualifiedRepository.toLowerCase() === prHeadRepoFullName.toLowerCase()
+  const refMatchesPullPattern = PR_REF_PATTERN.test(input.ref)
+  const commitMatchesPrHeadSha =
+    !!input.commit && prShas.includes(input.commit.toLowerCase())
+
+  if (
+    !repositoryMatchesPrHead &&
+    !refMatchesPullPattern &&
+    !commitMatchesPrHeadSha
+  ) {
+    return
+  }
+
+  throw new Error(
+    `Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
+      `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
+      `cache scope, and runner access. Fetching and executing a fork's code in that trusted ` +
+      `context commonly leads to "pwn request" vulnerabilities. To opt in, review the risks ` +
+      `at https://gh.io/securely-using-pull_request_target and set 'allow-unsafe-pr-checkout: true' ` +
+      `on the actions/checkout step.`
+  )
+}
+
+function pushIfSha(target: string[], value: unknown): void {
+  if (typeof value === 'string' && value.length > 0) {
+    target.push(value.toLowerCase())
+  }
+}

src/url-helper.ts

@@ -1,6 +1,6 @@
 import * as assert from 'assert'
 import {URL} from 'url'
-import {IGitSourceSettings} from './git-source-settings'
+import {IGitSourceSettings} from './git-source-settings.js'
 
 export function getFetchUrl(settings: IGitSourceSettings): string {
   assert.ok(

tsconfig.json

@@ -1,17 +1,13 @@
 {
   "compilerOptions": {
-    "target": "es6",
-    "module": "commonjs",
-    "lib": [
-      "es6"
-    ],
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
     "outDir": "./lib",
     "rootDir": "./src",
-    "declaration": true,
     "strict": true,
     "noImplicitAny": false,
-    "esModuleInterop": true,
-    "skipLibCheck": true
+    "esModuleInterop": true
   },
-  "exclude": ["__test__", "lib", "node_modules"]
+  "exclude": ["__test__", "lib", "node_modules", "jest.config.ts"]
 }