Add new public key for known_hosts (#1237)

* Add new public key for known_hosts

* Fix the build!

.eslintrc.json

@@ -1,6 +1,6 @@
 {
   "plugins": ["jest", "@typescript-eslint"],
-  "extends": ["plugin:github/es6"],
+  "extends": ["plugin:github/recommended"],
   "parser": "@typescript-eslint/parser",
   "parserOptions": {
     "ecmaVersion": 9,
@@ -16,23 +16,19 @@
     "@typescript-eslint/no-require-imports": "error",
     "@typescript-eslint/array-type": "error",
     "@typescript-eslint/await-thenable": "error",
-    "@typescript-eslint/ban-ts-ignore": "error",
     "camelcase": "off",
-    "@typescript-eslint/camelcase": "error",
-    "@typescript-eslint/class-name-casing": "error",
     "@typescript-eslint/explicit-function-return-type": ["error", {"allowExpressions": true}],
     "@typescript-eslint/func-call-spacing": ["error", "never"],
-    "@typescript-eslint/generic-type-naming": ["error", "^[A-Z][A-Za-z]*$"],
     "@typescript-eslint/no-array-constructor": "error",
     "@typescript-eslint/no-empty-interface": "error",
     "@typescript-eslint/no-explicit-any": "error",
     "@typescript-eslint/no-extraneous-class": "error",
+    "@typescript-eslint/no-floating-promises": "error",
     "@typescript-eslint/no-for-in-array": "error",
     "@typescript-eslint/no-inferrable-types": "error",
     "@typescript-eslint/no-misused-new": "error",
     "@typescript-eslint/no-namespace": "error",
     "@typescript-eslint/no-non-null-assertion": "warn",
-    "@typescript-eslint/no-object-literal-type-assertion": "error",
     "@typescript-eslint/no-unnecessary-qualifier": "error",
     "@typescript-eslint/no-unnecessary-type-assertion": "error",
     "@typescript-eslint/no-useless-constructor": "error",
@@ -40,7 +36,6 @@
     "@typescript-eslint/prefer-for-of": "warn",
     "@typescript-eslint/prefer-function-type": "warn",
     "@typescript-eslint/prefer-includes": "error",
-    "@typescript-eslint/prefer-interface": "error",
     "@typescript-eslint/prefer-string-starts-ends-with": "error",
     "@typescript-eslint/promise-function-async": "error",
     "@typescript-eslint/require-array-sort-compare": "error",

.gitattributes

@@ -0,0 +1 @@
+.licenses/** -diff linguist-generated=true

.github/workflows/check-dist.yml

@@ -0,0 +1,51 @@
+# `dist/index.js` is a special file in Actions.
+# When you reference an action with `uses:` in a workflow,
+# `index.js` is the code that will run.
+# For our project, we generate this file through a build process
+# from other source files.
+# We need to make sure the checked-in `index.js` actually matches what we expect it to be.
+name: Check dist
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - '**.md'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+  workflow_dispatch:
+
+jobs:
+  check-dist:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set Node.js 16.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 16.x
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Rebuild the index.js file
+        run: npm run build
+
+      - name: Compare the expected and actual dist/ directories
+        run: |
+          if [ "$(git diff --ignore-space-at-eol dist/ | wc -l)" -gt "0" ]; then
+            echo "Detected uncommitted changes after build.  See status below:"
+            git diff
+            exit 1
+          fi
+
+      # If dist/ was different than expected, upload the expected version as an artifact
+      - uses: actions/upload-artifact@v2
+        if: ${{ failure() && steps.diff.conclusion == 'failure' }}
+        with:
+          name: dist
+          path: dist/

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,58 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  schedule:
+    - cron: '28 9 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'javascript' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v3
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v2
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    - run: npm ci
+    - run: npm run build
+    - run: rm -rf dist # We want code scanning to analyze lib instead (individual .js files)
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v2

.github/workflows/licensed.yml

@@ -0,0 +1,14 @@
+name: Licensed
+
+on:
+  push: {branches: main}
+  pull_request: {branches: main}
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    name: Check licenses
+    steps:
+      - uses: actions/checkout@v3
+      - run: npm ci
+      - run: npm run licensed-check

.github/workflows/test.yml

@@ -4,20 +4,21 @@ on:
   pull_request:
   push:
     branches:
-      - master
+      - main
       - releases/*
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1 # todo: switch to v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 16.x
+      - uses: actions/checkout@v3
       - run: npm ci
       - run: npm run build
       - run: npm run format-check
       - run: npm run lint
-      - run: npm run pack
-      - run: npm run gendocs
       - run: npm test
       - name: Verify no unstaged changes
         run: __test__/verify-no-unstaged-changes.sh
@@ -31,10 +32,10 @@ jobs:
     steps:
       # Clone this repo
       - name: Checkout
-        uses: actions/checkout@v2-beta
+        uses: actions/checkout@v3
 
       # Basic checkout
-      - name: Basic checkout
+      - name: Checkout basic
         uses: ./
         with:
           ref: test-data/v2/basic
@@ -47,7 +48,7 @@ jobs:
       - name: Modify work tree
         shell: bash
         run: __test__/modify-work-tree.sh
-      - name: Clean checkout
+      - name: Checkout clean
         uses: ./
         with:
           ref: test-data/v2/basic
@@ -57,12 +58,12 @@ jobs:
         run: __test__/verify-clean.sh
 
       # Side by side
-      - name: Side by side checkout 1
+      - name: Checkout side by side 1
         uses: ./
         with:
           ref: test-data/v2/side-by-side-1
           path: side-by-side-1
-      - name: Side by side checkout 2
+      - name: Checkout side by side 2
         uses: ./
         with:
           ref: test-data/v2/side-by-side-2
@@ -72,7 +73,7 @@ jobs:
         run: __test__/verify-side-by-side.sh
 
       # LFS
-      - name: LFS checkout
+      - name: Checkout LFS
         uses: ./
         with:
           repository: actions/checkout # hardcoded, otherwise doesn't work from a fork
@@ -83,20 +84,162 @@ jobs:
         shell: bash
         run: __test__/verify-lfs.sh
 
-  test-job-container:
-    runs-on: ubuntu-latest
-    container: alpine:latest
-    steps:
-      # Clone this repo
-      # todo: after v2-beta contains the latest changes, switch this to "uses: actions/checkout@v2-beta"
-      - name: Checkout
-        uses: actions/checkout@a572f640b07e96fc5837b3adfa0e5a2ddd8dae21
+      # Submodules false
+      - name: Checkout submodules false
+        uses: ./
+        with:
+          ref: test-data/v2/submodule-ssh-url
+          path: submodules-false
+      - name: Verify submodules false
+        run: __test__/verify-submodules-false.sh
 
-      # Basic checkout
-      - name: Basic checkout
+      # Submodules one level
+      - name: Checkout submodules true
+        uses: ./
+        with:
+          ref: test-data/v2/submodule-ssh-url
+          path: submodules-true
+          submodules: true
+      - name: Verify submodules true
+        run: __test__/verify-submodules-true.sh
+
+      # Submodules recursive
+      - name: Checkout submodules recursive
+        uses: ./
+        with:
+          ref: test-data/v2/submodule-ssh-url
+          path: submodules-recursive
+          submodules: recursive
+      - name: Verify submodules recursive
+        run: __test__/verify-submodules-recursive.sh
+
+      # Basic checkout using REST API
+      - name: Remove basic
+        if: runner.os != 'windows'
+        run: rm -rf basic
+      - name: Remove basic (Windows)
+        if: runner.os == 'windows'
+        shell: cmd
+        run: rmdir /s /q basic
+      - name: Override git version
+        if: runner.os != 'windows'
+        run: __test__/override-git-version.sh
+      - name: Override git version (Windows)
+        if: runner.os == 'windows'
+        run: __test__\\override-git-version.cmd
+      - name: Checkout basic using REST API
         uses: ./
         with:
           ref: test-data/v2/basic
           path: basic
       - name: Verify basic
         run: __test__/verify-basic.sh --archive
+
+  test-proxy:
+    runs-on: ubuntu-latest
+    container:
+      image: alpine/git:latest
+      options: --dns 127.0.0.1
+    services:
+      squid-proxy:
+        image: ubuntu/squid:latest
+        ports:
+          - 3128:3128
+    env:
+      https_proxy: http://squid-proxy:3128
+    steps:
+      # Clone this repo
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # Basic checkout using git
+      - name: Checkout basic
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: basic
+      - name: Verify basic
+        run: __test__/verify-basic.sh
+
+      # Basic checkout using REST API
+      - name: Remove basic
+        run: rm -rf basic
+      - name: Override git version
+        run: __test__/override-git-version.sh
+      - name: Basic checkout using REST API
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: basic
+      - name: Verify basic
+        run: __test__/verify-basic.sh --archive
+
+  test-bypass-proxy:
+    runs-on: ubuntu-latest
+    env:
+      https_proxy: http://no-such-proxy:3128
+      no_proxy: api.github.com,github.com
+    steps:
+      # Clone this repo
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # Basic checkout using git
+      - name: Checkout basic
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: basic
+      - name: Verify basic
+        run: __test__/verify-basic.sh
+      - name: Remove basic
+        run: rm -rf basic
+
+      # Basic checkout using REST API
+      - name: Override git version
+        run: __test__/override-git-version.sh
+      - name: Checkout basic using REST API
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: basic
+      - name: Verify basic
+        run: __test__/verify-basic.sh --archive
+    
+  test-git-container:
+    runs-on: ubuntu-latest
+    container: bitnami/git:latest
+    steps:
+      # Clone this repo
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          path: v3
+
+      # Basic checkout using git
+      - name: Checkout basic
+        uses: ./v3
+        with:
+          ref: test-data/v2/basic
+      - name: Verify basic
+        run: |
+          if [ ! -f "./basic-file.txt" ]; then
+              echo "Expected basic file does not exist"
+              exit 1
+          fi
+
+          # Verify .git folder
+          if [ ! -d "./.git" ]; then
+            echo "Expected ./.git folder to exist"
+            exit 1
+          fi
+
+          # Verify auth token
+          git config --global --add safe.directory "*"
+          git fetch --no-tags --depth=1 origin +refs/heads/main:refs/remotes/origin/main
+
+      # needed to make checkout post cleanup succeed
+      - name: Fix Checkout v3
+        uses: actions/checkout@v3
+        with:
+          path: v3

.github/workflows/update-main-version.yml

@@ -0,0 +1,31 @@
+name: Update Main Version
+run-name: Move ${{ github.event.inputs.major_version }} to ${{ github.event.inputs.target }}
+
+on:
+  workflow_dispatch:
+    inputs:
+      target:
+        description: The tag or reference to use
+        required: true
+      major_version:
+        type: choice
+        description: The major version to update
+        options:
+          - v3
+          - v2
+
+jobs:
+  tag:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+    - name: Git config
+      run: |
+        git config user.name github-actions
+        git config user.email github-actions@github.com
+    - name: Tag new target
+      run: git tag -f ${{ github.event.inputs.major_version }} ${{ github.event.inputs.target }}
+    - name: Push new tag
+      run: git push origin ${{ github.event.inputs.major_version }} --force

.gitignore

@@ -1,2 +1,5 @@
+__test__/_temp
+_temp/
 lib/
-node_modules/
+node_modules/
+.vscode/

.licensed.yml

@@ -0,0 +1,14 @@
+sources:
+  npm: true
+
+allowed:
+  - apache-2.0
+  - bsd-2-clause
+  - bsd-3-clause
+  - isc
+  - mit
+  - cc0-1.0
+  - unlicense
+
+reviewed:
+  npm:

CHANGELOG.md

@@ -1,5 +1,72 @@
 # Changelog
 
+## v3.4.0
+- [Upgrade codeql actions to v2](https://github.com/actions/checkout/pull/1209)
+- [Upgrade dependencies](https://github.com/actions/checkout/pull/1210)
+- [Upgrade @actions/io](https://github.com/actions/checkout/pull/1225)
+
+## v3.3.0
+- [Implement branch list using callbacks from exec function](https://github.com/actions/checkout/pull/1045)
+- [Add in explicit reference to private checkout options](https://github.com/actions/checkout/pull/1050)
+- [Fix comment typos (that got added in #770)](https://github.com/actions/checkout/pull/1057)
+
+## v3.2.0
+- [Add GitHub Action to perform release](https://github.com/actions/checkout/pull/942)
+- [Fix status badge](https://github.com/actions/checkout/pull/967)
+- [Replace datadog/squid with ubuntu/squid Docker image](https://github.com/actions/checkout/pull/1002)
+- [Wrap pipeline commands for submoduleForeach in quotes](https://github.com/actions/checkout/pull/964)
+- [Update @actions/io to 1.1.2](https://github.com/actions/checkout/pull/1029)
+- [Upgrading version to 3.2.0](https://github.com/actions/checkout/pull/1039)
+
+## v3.1.0
+- [Use @actions/core `saveState` and `getState`](https://github.com/actions/checkout/pull/939)
+- [Add `github-server-url` input](https://github.com/actions/checkout/pull/922)
+
+## v3.0.2
+- [Add input `set-safe-directory`](https://github.com/actions/checkout/pull/770)
+
+## v3.0.1
+- [Fixed an issue where checkout failed to run in container jobs due to the new git setting `safe.directory`](https://github.com/actions/checkout/pull/762)
+- [Bumped various npm package versions](https://github.com/actions/checkout/pull/744)
+
+## v3.0.0
+
+- [Update to node 16](https://github.com/actions/checkout/pull/689)
+
+## v2.3.1
+
+- [Fix default branch resolution for .wiki and when using SSH](https://github.com/actions/checkout/pull/284)
+
+## v2.3.0
+
+- [Fallback to the default branch](https://github.com/actions/checkout/pull/278)
+
+## v2.2.0
+
+- [Fetch all history for all tags and branches when fetch-depth=0](https://github.com/actions/checkout/pull/258)
+
+## v2.1.1
+
+- Changes to support GHES ([here](https://github.com/actions/checkout/pull/236) and [here](https://github.com/actions/checkout/pull/248))
+
+## v2.1.0
+
+- [Group output](https://github.com/actions/checkout/pull/191)
+- [Changes to support GHES alpha release](https://github.com/actions/checkout/pull/199)
+- [Persist core.sshCommand for submodules](https://github.com/actions/checkout/pull/184)
+- [Add support ssh](https://github.com/actions/checkout/pull/163)
+- [Convert submodule SSH URL to HTTPS, when not using SSH](https://github.com/actions/checkout/pull/179)
+- [Add submodule support](https://github.com/actions/checkout/pull/157)
+- [Follow proxy settings](https://github.com/actions/checkout/pull/144)
+- [Fix ref for pr closed event when a pr is merged](https://github.com/actions/checkout/pull/141)
+- [Fix issue checking detached when git less than 2.22](https://github.com/actions/checkout/pull/128)
+
+## v2.0.0
+
+- [Do not pass cred on command line](https://github.com/actions/checkout/pull/108)
+- [Add input persist-credentials](https://github.com/actions/checkout/pull/107)
+- [Fallback to REST API to download repo](https://github.com/actions/checkout/pull/104)
+
 ## v2 (beta)
 
 - Improved fetch performance

CODEOWNERS

@@ -0,0 +1 @@
+* @actions/actions-runtime

CONTRIBUTING.md

@@ -0,0 +1,28 @@
+# Contributing
+
+## Submitting a pull request
+
+1. Fork and clone the repository
+1. Configure and install the dependencies: `npm install`
+1. Create a new branch: `git checkout -b my-branch-name`
+1. Make your change, add tests, and make sure the tests still pass: `npm run test`
+1. Make sure your code is correctly formatted: `npm run format`
+1. Update `dist/index.js` using `npm run build`. This creates a single javascript file that is used as an entrypoint for the action
+1. Push to your fork and submit a pull request
+1. Pat yourself on the back and wait for your pull request to be reviewed and merged
+
+Here are a few things you can do that will increase the likelihood of your pull request being accepted:
+
+- Write tests.
+- Keep your change as focused as possible. If there are multiple changes you would like to make that are not dependent upon each other, consider submitting them as separate pull requests.
+
+## Resources
+
+- [How to Contribute to Open Source](https://opensource.guide/how-to-contribute/)
+- [Using Pull Requests](https://help.github.com/articles/about-pull-requests/)
+- [GitHub Help](https://help.github.com)
+- [Writing good commit messages](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
+
+Thanks! :heart: :heart: :heart:
+
+GitHub Actions Team :octocat:

README.md

@@ -1,41 +1,25 @@
-<p align="center">
-  <a href="https://github.com/actions/checkout"><img alt="GitHub Actions status" src="https://github.com/actions/checkout/workflows/test-local/badge.svg"></a>
-</p>
+[![Build and Test](https://github.com/actions/checkout/actions/workflows/test.yml/badge.svg)](https://github.com/actions/checkout/actions/workflows/test.yml)
 
-# Checkout V2 beta
+# Checkout V3
 
 This action checks-out your repository under `$GITHUB_WORKSPACE`, so your workflow can access it.
 
-By default, the repository that triggered the workflow is checked-out, for the ref/SHA that triggered the event.
+Only a single commit is fetched by default, for the ref/SHA that triggered the workflow. Set `fetch-depth: 0` to fetch all history for all branches and tags. Refer [here](https://help.github.com/en/articles/events-that-trigger-workflows) to learn which commit `$GITHUB_SHA` points to for different events.
 
-Refer [here](https://help.github.com/en/articles/events-that-trigger-workflows) to learn which commit `$GITHUB_SHA` points to for different events.
+The auth token is persisted in the local git config. This enables your scripts to run authenticated git commands. The token is removed during post-job cleanup. Set `persist-credentials: false` to opt-out.
+
+When Git 2.18 or higher is not in your PATH, falls back to the REST API to download the files.
 
 # What's new
 
-- Improved fetch performance
-  - The default behavior now fetches only the commit being checked-out
-- Script authenticated git commands
-  - Persists the input `token` in the local git config
-  - Enables your scripts to run authenticated git commands
-  - Post-job cleanup removes the token
-  - Opt out by setting the input `persist-credentials: false`
-- Creates a local branch
-  - No longer detached HEAD when checking out a branch
-  - A local branch is created with the corresponding upstream branch set
-- Improved layout
-  - The input `path` is always relative to $GITHUB_WORKSPACE
-  - Aligns better with container actions, where $GITHUB_WORKSPACE gets mapped in
-- Fallback to REST API download
-  - When Git 2.18 or higher is not in the PATH, the REST API will be used to download the files
-- Removed input `submodules`
-
-Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous versions.
+- Updated to the node16 runtime by default
+  - This requires a minimum [Actions Runner](https://github.com/actions/runner/releases/tag/v2.285.0) version of v2.285.0 to run, which is by default available in GHES 3.4 or later.
 
 # Usage
 
 <!-- start usage -->
 ```yaml
-- uses: actions/checkout@v2-beta
+- uses: actions/checkout@v3
   with:
     # Repository name with owner. For example, actions/checkout
     # Default: ${{ github.repository }}
@@ -43,16 +27,43 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
 
     # The branch, tag or SHA to checkout. When checking out the repository that
     # triggered a workflow, this defaults to the reference or SHA for that event.
-    # Otherwise, defaults to `master`.
+    # Otherwise, uses the default branch.
     ref: ''
 
-    # Auth token used to fetch the repository. The token is stored in the local git
-    # config, which enables your scripts to run authenticated git commands. The
-    # post-job step removes the token from the git config.
+    # Personal access token (PAT) used to fetch the repository. The PAT is configured
+    # with the local git config, which enables your scripts to run authenticated git
+    # commands. The post-job step removes the PAT.
+    #
+    # We recommend using a service account with the least permissions necessary. Also
+    # when generating a new PAT, select the least scopes necessary.
+    #
+    # [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+    #
     # Default: ${{ github.token }}
     token: ''
 
-    # Whether to persist the token in the git config
+    # SSH key used to fetch the repository. The SSH key is configured with the local
+    # git config, which enables your scripts to run authenticated git commands. The
+    # post-job step removes the SSH key.
+    #
+    # We recommend using a service account with the least permissions necessary.
+    #
+    # [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+    ssh-key: ''
+
+    # Known hosts in addition to the user and global host key database. The public SSH
+    # keys for a host may be obtained using the utility `ssh-keyscan`. For example,
+    # `ssh-keyscan github.com`. The public key for github.com is always implicitly
+    # added.
+    ssh-known-hosts: ''
+
+    # Whether to perform strict host key checking. When true, adds the options
+    # `StrictHostKeyChecking=yes` and `CheckHostIP=no` to the SSH command line. Use
+    # the input `ssh-known-hosts` to configure additional hosts.
+    # Default: true
+    ssh-strict: ''
+
+    # Whether to configure the token or SSH key with the local git config
     # Default: true
     persist-credentials: ''
 
@@ -63,43 +74,162 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
     # Default: true
     clean: ''
 
-    # Number of commits to fetch. 0 indicates all history.
+    # Number of commits to fetch. 0 indicates all history for all branches and tags.
     # Default: 1
     fetch-depth: ''
 
     # Whether to download Git-LFS files
     # Default: false
     lfs: ''
+
+    # Whether to checkout submodules: `true` to checkout submodules or `recursive` to
+    # recursively checkout submodules.
+    #
+    # When the `ssh-key` input is not provided, SSH URLs beginning with
+    # `git@github.com:` are converted to HTTPS.
+    #
+    # Default: false
+    submodules: ''
+
+    # Add repository path as safe.directory for Git global config by running `git
+    # config --global --add safe.directory <path>`
+    # Default: true
+    set-safe-directory: ''
+
+    # 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
+    github-server-url: ''
 ```
 <!-- end usage -->
 
+# Scenarios
+
+- [Fetch all history for all tags and branches](#Fetch-all-history-for-all-tags-and-branches)
+- [Checkout a different branch](#Checkout-a-different-branch)
+- [Checkout HEAD^](#Checkout-HEAD)
+- [Checkout multiple repos (side by side)](#Checkout-multiple-repos-side-by-side)
+- [Checkout multiple repos (nested)](#Checkout-multiple-repos-nested)
+- [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+- [Checkout pull request HEAD commit instead of merge commit](#Checkout-pull-request-HEAD-commit-instead-of-merge-commit)
+- [Checkout pull request on closed event](#Checkout-pull-request-on-closed-event)
+- [Push a commit using the built-in token](#Push-a-commit-using-the-built-in-token)
+
+## Fetch all history for all tags and branches
+
+```yaml
+- uses: actions/checkout@v3
+  with:
+    fetch-depth: 0
+```
+
 ## Checkout a different branch
 
 ```yaml
-- uses: actions/checkout@v2-beta
+- uses: actions/checkout@v3
   with:
-    ref: some-branch
+    ref: my-branch
 ```
 
-## Checkout a different, private repository
+## Checkout HEAD^
 
 ```yaml
-- uses: actions/checkout@v2-beta
+- uses: actions/checkout@v3
   with:
-    repository: myAccount/myRepository
-    ref: refs/heads/master
-    token: ${{ secrets.GitHub_PAT }} # `GitHub_PAT` is a secret that contains your PAT
+    fetch-depth: 2
+- run: git checkout HEAD^
 ```
-> - `${{ github.token }}` is scoped to the current repository, so if you want to checkout another repository that is private you will need to provide your own [PAT](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line).
 
-## Checkout the HEAD commit of a PR, rather than the merge commit
+## Checkout multiple repos (side by side)
 
 ```yaml
-- uses: actions/checkout@v2-beta
+- name: Checkout
+  uses: actions/checkout@v3
+  with:
+    path: main
+
+- name: Checkout tools repo
+  uses: actions/checkout@v3
+  with:
+    repository: my-org/my-tools
+    path: my-tools
+```
+> - If your secondary repository is private you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+
+## Checkout multiple repos (nested)
+
+```yaml
+- name: Checkout
+  uses: actions/checkout@v3
+
+- name: Checkout tools repo
+  uses: actions/checkout@v3
+  with:
+    repository: my-org/my-tools
+    path: my-tools
+```
+> - If your secondary repository is private you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+
+## Checkout multiple repos (private)
+
+```yaml
+- name: Checkout
+  uses: actions/checkout@v3
+  with:
+    path: main
+
+- name: Checkout private tools
+  uses: actions/checkout@v3
+  with:
+    repository: my-org/my-private-tools
+    token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
+    path: my-tools
+```
+
+> - `${{ github.token }}` is scoped to the current repository, so if you want to checkout a different repository that is private you will need to provide your own [PAT](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line).
+
+
+## Checkout pull request HEAD commit instead of merge commit
+
+```yaml
+- uses: actions/checkout@v3
   with:
     ref: ${{ github.event.pull_request.head.sha }}
 ```
 
+## Checkout pull request on closed event
+
+```yaml
+on:
+  pull_request:
+    branches: [main]
+    types: [opened, synchronize, closed]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+```
+
+## Push a commit using the built-in token
+
+```yaml
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - run: |
+          date > generated.txt
+          git config user.name github-actions
+          git config user.email github-actions@github.com
+          git add .
+          git commit -m "generated"
+          git push
+```
+
 # License
 
 The scripts and documentation in this project are released under the [MIT License](LICENSE)

__test__/git-auth-helper.test.ts

@@ -0,0 +1,843 @@
+import * as core from '@actions/core'
+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'
+
+const isWindows = process.platform === 'win32'
+const testWorkspace = path.join(__dirname, '_temp', 'git-auth-helper')
+const originalRunnerTemp = process.env['RUNNER_TEMP']
+const originalHome = process.env['HOME']
+let workspace: string
+let localGitConfigPath: string
+let globalGitConfigPath: string
+let runnerTemp: string
+let tempHomedir: string
+let git: IGitCommandManager & {env: {[key: string]: string}}
+let settings: IGitSourceSettings
+let sshPath: string
+let githubServerUrl: string
+
+describe('git-auth-helper tests', () => {
+  beforeAll(async () => {
+    // SSH
+    sshPath = await io.which('ssh')
+
+    // Clear test workspace
+    await io.rmRF(testWorkspace)
+  })
+
+  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())
+  })
+
+  afterEach(() => {
+    // Unregister mocks
+    jest.restoreAllMocks()
+
+    // Restore HOME
+    if (originalHome) {
+      process.env['HOME'] = originalHome
+    } else {
+      delete process.env['HOME']
+    }
+  })
+
+  afterAll(() => {
+    // Restore RUNNER_TEMP
+    delete process.env['RUNNER_TEMP']
+    if (originalRunnerTemp) {
+      process.env['RUNNER_TEMP'] = originalRunnerTemp
+    }
+  })
+
+  async function testAuthHeader(
+    testName: string,
+    serverUrl: string | undefined = undefined
+  ) {
+    // Arrange
+    let expectedServerUrl = 'https://github.com'
+    if (serverUrl) {
+      githubServerUrl = serverUrl
+      expectedServerUrl = githubServerUrl
+    }
+
+    await setup(testName)
+    expect(settings.authToken).toBeTruthy() // sanity check
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert config
+    const configContent = (
+      await fs.promises.readFile(localGitConfigPath)
+    ).toString()
+    const basicCredential = Buffer.from(
+      `x-access-token:${settings.authToken}`,
+      'utf8'
+    ).toString('base64')
+    expect(
+      configContent.indexOf(
+        `http.${expectedServerUrl}/.extraheader AUTHORIZATION: basic ${basicCredential}`
+      )
+    ).toBeGreaterThanOrEqual(0)
+  }
+
+  const configureAuth_configuresAuthHeader =
+    'configureAuth configures auth header'
+  it(configureAuth_configuresAuthHeader, async () => {
+    await testAuthHeader(configureAuth_configuresAuthHeader)
+  })
+
+  const configureAuth_AcceptsGitHubServerUrl =
+    'inject https://my-ghes-server.com as github server url'
+  it(configureAuth_AcceptsGitHubServerUrl, async () => {
+    await testAuthHeader(
+      configureAuth_AcceptsGitHubServerUrl,
+      'https://my-ghes-server.com'
+    )
+  })
+
+  const configureAuth_AcceptsGitHubServerUrlSetToGHEC =
+    'inject https://github.com as github server url'
+  it(configureAuth_AcceptsGitHubServerUrlSetToGHEC, async () => {
+    await testAuthHeader(
+      configureAuth_AcceptsGitHubServerUrl,
+      'https://github.com'
+    )
+  })
+
+  const configureAuth_configuresAuthHeaderEvenWhenPersistCredentialsFalse =
+    'configureAuth configures auth header even when persist credentials false'
+  it(
+    configureAuth_configuresAuthHeaderEvenWhenPersistCredentialsFalse,
+    async () => {
+      // Arrange
+      await setup(
+        configureAuth_configuresAuthHeaderEvenWhenPersistCredentialsFalse
+      )
+      expect(settings.authToken).toBeTruthy() // sanity check
+      settings.persistCredentials = false
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+      // Act
+      await authHelper.configureAuth()
+
+      // Assert config
+      const configContent = (
+        await fs.promises.readFile(localGitConfigPath)
+      ).toString()
+      expect(
+        configContent.indexOf(
+          `http.https://github.com/.extraheader AUTHORIZATION`
+        )
+      ).toBeGreaterThanOrEqual(0)
+    }
+  )
+
+  const configureAuth_copiesUserKnownHosts =
+    'configureAuth copies user known hosts'
+  it(configureAuth_copiesUserKnownHosts, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${configureAuth_copiesUserKnownHosts}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arange
+    await setup(configureAuth_copiesUserKnownHosts)
+    expect(settings.sshKey).toBeTruthy() // sanity check
+
+    // Mock fs.promises.readFile
+    const realReadFile = fs.promises.readFile
+    jest.spyOn(fs.promises, 'readFile').mockImplementation(
+      async (file: any, options: any): Promise<Buffer> => {
+        const userKnownHostsPath = path.join(
+          os.homedir(),
+          '.ssh',
+          'known_hosts'
+        )
+        if (file === userKnownHostsPath) {
+          return Buffer.from('some-domain.com ssh-rsa ABCDEF')
+        }
+
+        return await realReadFile(file, options)
+      }
+    )
+
+    // Act
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    await authHelper.configureAuth()
+
+    // Assert known hosts
+    const actualSshKnownHostsPath = await getActualSshKnownHostsPath()
+    const actualSshKnownHostsContent = (
+      await fs.promises.readFile(actualSshKnownHostsPath)
+    ).toString()
+    expect(actualSshKnownHostsContent).toMatch(
+      /some-domain\.com ssh-rsa ABCDEF/
+    )
+    expect(actualSshKnownHostsContent).toMatch(/github\.com ssh-rsa AAAAB3N/)
+  })
+
+  const configureAuth_registersBasicCredentialAsSecret =
+    'configureAuth registers basic credential as secret'
+  it(configureAuth_registersBasicCredentialAsSecret, async () => {
+    // Arrange
+    await setup(configureAuth_registersBasicCredentialAsSecret)
+    expect(settings.authToken).toBeTruthy() // sanity check
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert secret
+    const setSecretSpy = core.setSecret as jest.Mock<any, any>
+    expect(setSecretSpy).toHaveBeenCalledTimes(1)
+    const expectedSecret = Buffer.from(
+      `x-access-token:${settings.authToken}`,
+      'utf8'
+    ).toString('base64')
+    expect(setSecretSpy).toHaveBeenCalledWith(expectedSecret)
+  })
+
+  const setsSshCommandEnvVarWhenPersistCredentialsFalse =
+    'sets SSH command env var when persist-credentials false'
+  it(setsSshCommandEnvVarWhenPersistCredentialsFalse, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${setsSshCommandEnvVarWhenPersistCredentialsFalse}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arrange
+    await setup(setsSshCommandEnvVarWhenPersistCredentialsFalse)
+    settings.persistCredentials = false
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert git env var
+    const actualKeyPath = await getActualSshKeyPath()
+    const actualKnownHostsPath = await getActualSshKnownHostsPath()
+    const expectedSshCommand = `"${sshPath}" -i "$RUNNER_TEMP/${path.basename(
+      actualKeyPath
+    )}" -o StrictHostKeyChecking=yes -o CheckHostIP=no -o "UserKnownHostsFile=$RUNNER_TEMP/${path.basename(
+      actualKnownHostsPath
+    )}"`
+    expect(git.setEnvironmentVariable).toHaveBeenCalledWith(
+      'GIT_SSH_COMMAND',
+      expectedSshCommand
+    )
+
+    // Asserty git config
+    const gitConfigLines = (await fs.promises.readFile(localGitConfigPath))
+      .toString()
+      .split('\n')
+      .filter(x => x)
+    expect(gitConfigLines).toHaveLength(1)
+    expect(gitConfigLines[0]).toMatch(/^http\./)
+  })
+
+  const configureAuth_setsSshCommandWhenPersistCredentialsTrue =
+    'sets SSH command when persist-credentials true'
+  it(configureAuth_setsSshCommandWhenPersistCredentialsTrue, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${configureAuth_setsSshCommandWhenPersistCredentialsTrue}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arrange
+    await setup(configureAuth_setsSshCommandWhenPersistCredentialsTrue)
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert git env var
+    const actualKeyPath = await getActualSshKeyPath()
+    const actualKnownHostsPath = await getActualSshKnownHostsPath()
+    const expectedSshCommand = `"${sshPath}" -i "$RUNNER_TEMP/${path.basename(
+      actualKeyPath
+    )}" -o StrictHostKeyChecking=yes -o CheckHostIP=no -o "UserKnownHostsFile=$RUNNER_TEMP/${path.basename(
+      actualKnownHostsPath
+    )}"`
+    expect(git.setEnvironmentVariable).toHaveBeenCalledWith(
+      'GIT_SSH_COMMAND',
+      expectedSshCommand
+    )
+
+    // Asserty git config
+    expect(git.config).toHaveBeenCalledWith(
+      'core.sshCommand',
+      expectedSshCommand
+    )
+  })
+
+  const configureAuth_writesExplicitKnownHosts = 'writes explicit known hosts'
+  it(configureAuth_writesExplicitKnownHosts, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${configureAuth_writesExplicitKnownHosts}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arrange
+    await setup(configureAuth_writesExplicitKnownHosts)
+    expect(settings.sshKey).toBeTruthy() // sanity check
+    settings.sshKnownHosts = 'my-custom-host.com ssh-rsa ABC123'
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert known hosts
+    const actualSshKnownHostsPath = await getActualSshKnownHostsPath()
+    const actualSshKnownHostsContent = (
+      await fs.promises.readFile(actualSshKnownHostsPath)
+    ).toString()
+    expect(actualSshKnownHostsContent).toMatch(
+      /my-custom-host\.com ssh-rsa ABC123/
+    )
+    expect(actualSshKnownHostsContent).toMatch(/github\.com ssh-rsa AAAAB3N/)
+  })
+
+  const configureAuth_writesSshKeyAndImplicitKnownHosts =
+    'writes SSH key and implicit known hosts'
+  it(configureAuth_writesSshKeyAndImplicitKnownHosts, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${configureAuth_writesSshKeyAndImplicitKnownHosts}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arrange
+    await setup(configureAuth_writesSshKeyAndImplicitKnownHosts)
+    expect(settings.sshKey).toBeTruthy() // sanity check
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+
+    // Assert SSH key
+    const actualSshKeyPath = await getActualSshKeyPath()
+    expect(actualSshKeyPath).toBeTruthy()
+    const actualSshKeyContent = (
+      await fs.promises.readFile(actualSshKeyPath)
+    ).toString()
+    expect(actualSshKeyContent).toBe(settings.sshKey + '\n')
+    if (!isWindows) {
+      // Assert read/write for user, not group or others.
+      // Otherwise SSH client will error.
+      expect((await fs.promises.stat(actualSshKeyPath)).mode & 0o777).toBe(
+        0o600
+      )
+    }
+
+    // Assert known hosts
+    const actualSshKnownHostsPath = await getActualSshKnownHostsPath()
+    const actualSshKnownHostsContent = (
+      await fs.promises.readFile(actualSshKnownHostsPath)
+    ).toString()
+    expect(actualSshKnownHostsContent).toMatch(/github\.com ssh-rsa AAAAB3N/)
+  })
+
+  const configureGlobalAuth_configuresUrlInsteadOfWhenSshKeyNotSet =
+    'configureGlobalAuth configures URL insteadOf when SSH key not set'
+  it(configureGlobalAuth_configuresUrlInsteadOfWhenSshKeyNotSet, async () => {
+    // Arrange
+    await setup(configureGlobalAuth_configuresUrlInsteadOfWhenSshKeyNotSet)
+    settings.sshKey = ''
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+    await authHelper.configureGlobalAuth()
+
+    // Assert temporary global config
+    expect(git.env['HOME']).toBeTruthy()
+    const configContent = (
+      await fs.promises.readFile(path.join(git.env['HOME'], '.gitconfig'))
+    ).toString()
+    expect(
+      configContent.indexOf(`url.https://github.com/.insteadOf git@github.com`)
+    ).toBeGreaterThanOrEqual(0)
+  })
+
+  const configureGlobalAuth_copiesGlobalGitConfig =
+    'configureGlobalAuth copies global git config'
+  it(configureGlobalAuth_copiesGlobalGitConfig, async () => {
+    // Arrange
+    await setup(configureGlobalAuth_copiesGlobalGitConfig)
+    await fs.promises.writeFile(globalGitConfigPath, 'value-from-global-config')
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Act
+    await authHelper.configureAuth()
+    await authHelper.configureGlobalAuth()
+
+    // Assert original global config not altered
+    let configContent = (
+      await fs.promises.readFile(globalGitConfigPath)
+    ).toString()
+    expect(configContent).toBe('value-from-global-config')
+
+    // Assert temporary global config
+    expect(git.env['HOME']).toBeTruthy()
+    const basicCredential = Buffer.from(
+      `x-access-token:${settings.authToken}`,
+      'utf8'
+    ).toString('base64')
+    configContent = (
+      await fs.promises.readFile(path.join(git.env['HOME'], '.gitconfig'))
+    ).toString()
+    expect(
+      configContent.indexOf('value-from-global-config')
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      configContent.indexOf(
+        `http.https://github.com/.extraheader AUTHORIZATION: basic ${basicCredential}`
+      )
+    ).toBeGreaterThanOrEqual(0)
+  })
+
+  const configureGlobalAuth_createsNewGlobalGitConfigWhenGlobalDoesNotExist =
+    'configureGlobalAuth creates new git config when global does not exist'
+  it(
+    configureGlobalAuth_createsNewGlobalGitConfigWhenGlobalDoesNotExist,
+    async () => {
+      // Arrange
+      await setup(
+        configureGlobalAuth_createsNewGlobalGitConfigWhenGlobalDoesNotExist
+      )
+      await io.rmRF(globalGitConfigPath)
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+      // Act
+      await authHelper.configureAuth()
+      await authHelper.configureGlobalAuth()
+
+      // Assert original global config not recreated
+      try {
+        await fs.promises.stat(globalGitConfigPath)
+        throw new Error(
+          `Did not expect file to exist: '${globalGitConfigPath}'`
+        )
+      } catch (err) {
+        if ((err as any)?.code !== 'ENOENT') {
+          throw err
+        }
+      }
+
+      // Assert temporary global config
+      expect(git.env['HOME']).toBeTruthy()
+      const basicCredential = Buffer.from(
+        `x-access-token:${settings.authToken}`,
+        'utf8'
+      ).toString('base64')
+      const configContent = (
+        await fs.promises.readFile(path.join(git.env['HOME'], '.gitconfig'))
+      ).toString()
+      expect(
+        configContent.indexOf(
+          `http.https://github.com/.extraheader AUTHORIZATION: basic ${basicCredential}`
+        )
+      ).toBeGreaterThanOrEqual(0)
+    }
+  )
+
+  const configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeyNotSet =
+    'configureSubmoduleAuth configures submodules when persist credentials false and SSH key not set'
+  it(
+    configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeyNotSet,
+    async () => {
+      // Arrange
+      await setup(
+        configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeyNotSet
+      )
+      settings.persistCredentials = false
+      settings.sshKey = ''
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+      await authHelper.configureAuth()
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      mockSubmoduleForeach.mockClear() // reset calls
+
+      // Act
+      await authHelper.configureSubmoduleAuth()
+
+      // Assert
+      expect(mockSubmoduleForeach).toBeCalledTimes(1)
+      expect(mockSubmoduleForeach.mock.calls[0][0] as string).toMatch(
+        /unset-all.*insteadOf/
+      )
+    }
+  )
+
+  const configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeySet =
+    'configureSubmoduleAuth configures submodules when persist credentials false and SSH key set'
+  it(
+    configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeySet,
+    async () => {
+      if (!sshPath) {
+        process.stdout.write(
+          `Skipped test "${configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeySet}". Executable 'ssh' not found in the PATH.\n`
+        )
+        return
+      }
+
+      // Arrange
+      await setup(
+        configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsFalseAndSshKeySet
+      )
+      settings.persistCredentials = false
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+      await authHelper.configureAuth()
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      mockSubmoduleForeach.mockClear() // reset calls
+
+      // Act
+      await authHelper.configureSubmoduleAuth()
+
+      // Assert
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(1)
+      expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
+        /unset-all.*insteadOf/
+      )
+    }
+  )
+
+  const configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeyNotSet =
+    'configureSubmoduleAuth configures submodules when persist credentials true and SSH key not set'
+  it(
+    configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeyNotSet,
+    async () => {
+      // Arrange
+      await setup(
+        configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeyNotSet
+      )
+      settings.sshKey = ''
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+      await authHelper.configureAuth()
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      mockSubmoduleForeach.mockClear() // reset calls
+
+      // Act
+      await authHelper.configureSubmoduleAuth()
+
+      // Assert
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(4)
+      expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
+        /unset-all.*insteadOf/
+      )
+      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/http.*extraheader/)
+      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(
+        /url.*insteadOf.*git@github.com:/
+      )
+      expect(mockSubmoduleForeach.mock.calls[3][0]).toMatch(
+        /url.*insteadOf.*org-123456@github.com:/
+      )
+    }
+  )
+
+  const configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeySet =
+    'configureSubmoduleAuth configures submodules when persist credentials true and SSH key set'
+  it(
+    configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeySet,
+    async () => {
+      if (!sshPath) {
+        process.stdout.write(
+          `Skipped test "${configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeySet}". Executable 'ssh' not found in the PATH.\n`
+        )
+        return
+      }
+
+      // Arrange
+      await setup(
+        configureSubmoduleAuth_configuresSubmodulesWhenPersistCredentialsTrueAndSshKeySet
+      )
+      const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+      await authHelper.configureAuth()
+      const mockSubmoduleForeach = git.submoduleForeach as jest.Mock<any, any>
+      mockSubmoduleForeach.mockClear() // reset calls
+
+      // Act
+      await authHelper.configureSubmoduleAuth()
+
+      // Assert
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(3)
+      expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
+        /unset-all.*insteadOf/
+      )
+      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/http.*extraheader/)
+      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(/core\.sshCommand/)
+    }
+  )
+
+  const removeAuth_removesSshCommand = 'removeAuth removes SSH command'
+  it(removeAuth_removesSshCommand, async () => {
+    if (!sshPath) {
+      process.stdout.write(
+        `Skipped test "${removeAuth_removesSshCommand}". Executable 'ssh' not found in the PATH.\n`
+      )
+      return
+    }
+
+    // Arrange
+    await setup(removeAuth_removesSshCommand)
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    await authHelper.configureAuth()
+    let gitConfigContent = (
+      await fs.promises.readFile(localGitConfigPath)
+    ).toString()
+    expect(gitConfigContent.indexOf('core.sshCommand')).toBeGreaterThanOrEqual(
+      0
+    ) // sanity check
+    const actualKeyPath = await getActualSshKeyPath()
+    expect(actualKeyPath).toBeTruthy()
+    await fs.promises.stat(actualKeyPath)
+    const actualKnownHostsPath = await getActualSshKnownHostsPath()
+    expect(actualKnownHostsPath).toBeTruthy()
+    await fs.promises.stat(actualKnownHostsPath)
+
+    // Act
+    await authHelper.removeAuth()
+
+    // Assert git config
+    gitConfigContent = (
+      await fs.promises.readFile(localGitConfigPath)
+    ).toString()
+    expect(gitConfigContent.indexOf('core.sshCommand')).toBeLessThan(0)
+
+    // Assert SSH key file
+    try {
+      await fs.promises.stat(actualKeyPath)
+      throw new Error('SSH key should have been deleted')
+    } catch (err) {
+      if ((err as any)?.code !== 'ENOENT') {
+        throw err
+      }
+    }
+
+    // Assert known hosts file
+    try {
+      await fs.promises.stat(actualKnownHostsPath)
+      throw new Error('SSH known hosts should have been deleted')
+    } catch (err) {
+      if ((err as any)?.code !== 'ENOENT') {
+        throw err
+      }
+    }
+  })
+
+  const removeAuth_removesToken = 'removeAuth removes token'
+  it(removeAuth_removesToken, async () => {
+    // Arrange
+    await setup(removeAuth_removesToken)
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    await authHelper.configureAuth()
+    let gitConfigContent = (
+      await fs.promises.readFile(localGitConfigPath)
+    ).toString()
+    expect(gitConfigContent.indexOf('http.')).toBeGreaterThanOrEqual(0) // sanity check
+
+    // Act
+    await authHelper.removeAuth()
+
+    // Assert git config
+    gitConfigContent = (
+      await fs.promises.readFile(localGitConfigPath)
+    ).toString()
+    expect(gitConfigContent.indexOf('http.')).toBeLessThan(0)
+  })
+
+  const removeGlobalConfig_removesOverride =
+    'removeGlobalConfig removes override'
+  it(removeGlobalConfig_removesOverride, async () => {
+    // Arrange
+    await setup(removeGlobalConfig_removesOverride)
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    await authHelper.configureAuth()
+    await authHelper.configureGlobalAuth()
+    const homeOverride = git.env['HOME'] // Sanity check
+    expect(homeOverride).toBeTruthy()
+    await fs.promises.stat(path.join(git.env['HOME'], '.gitconfig'))
+
+    // Act
+    await authHelper.removeGlobalConfig()
+
+    // Assert
+    expect(git.env['HOME']).toBeUndefined()
+    try {
+      await fs.promises.stat(homeOverride)
+      throw new Error(`Should have been deleted '${homeOverride}'`)
+    } catch (err) {
+      if ((err as any)?.code !== 'ENOENT') {
+        throw err
+      }
+    }
+  })
+})
+
+async function setup(testName: string): Promise<void> {
+  testName = testName.replace(/[^a-zA-Z0-9_]+/g, '-')
+
+  // Directories
+  workspace = path.join(testWorkspace, testName, 'workspace')
+  runnerTemp = path.join(testWorkspace, testName, 'runner-temp')
+  tempHomedir = path.join(testWorkspace, testName, 'home-dir')
+  await fs.promises.mkdir(workspace, {recursive: true})
+  await fs.promises.mkdir(runnerTemp, {recursive: true})
+  await fs.promises.mkdir(tempHomedir, {recursive: true})
+  process.env['RUNNER_TEMP'] = runnerTemp
+  process.env['HOME'] = tempHomedir
+
+  // Create git config
+  globalGitConfigPath = path.join(tempHomedir, '.gitconfig')
+  await fs.promises.writeFile(globalGitConfigPath, '')
+  localGitConfigPath = path.join(workspace, '.git', 'config')
+  await fs.promises.mkdir(path.dirname(localGitConfigPath), {recursive: true})
+  await fs.promises.writeFile(localGitConfigPath, '')
+
+  git = {
+    branchDelete: jest.fn(),
+    branchExists: jest.fn(),
+    branchList: jest.fn(),
+    checkout: jest.fn(),
+    checkoutDetach: jest.fn(),
+    config: jest.fn(
+      async (key: string, value: string, globalConfig?: boolean) => {
+        const configPath = globalConfig
+          ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+          : localGitConfigPath
+        await fs.promises.appendFile(configPath, `\n${key} ${value}`)
+      }
+    ),
+    configExists: jest.fn(
+      async (key: string, globalConfig?: boolean): Promise<boolean> => {
+        const configPath = globalConfig
+          ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+          : localGitConfigPath
+        const content = await fs.promises.readFile(configPath)
+        const lines = content
+          .toString()
+          .split('\n')
+          .filter(x => x)
+        return lines.some(x => x.startsWith(key))
+      }
+    ),
+    env: {},
+    fetch: jest.fn(),
+    getDefaultBranch: jest.fn(),
+    getWorkingDirectory: jest.fn(() => workspace),
+    init: jest.fn(),
+    isDetached: jest.fn(),
+    lfsFetch: jest.fn(),
+    lfsInstall: jest.fn(),
+    log1: jest.fn(),
+    remoteAdd: jest.fn(),
+    removeEnvironmentVariable: jest.fn((name: string) => delete git.env[name]),
+    revParse: jest.fn(),
+    setEnvironmentVariable: jest.fn((name: string, value: string) => {
+      git.env[name] = value
+    }),
+    shaExists: jest.fn(),
+    submoduleForeach: jest.fn(async () => {
+      return ''
+    }),
+    submoduleSync: jest.fn(),
+    submoduleUpdate: jest.fn(),
+    tagExists: jest.fn(),
+    tryClean: jest.fn(),
+    tryConfigUnset: jest.fn(
+      async (key: string, globalConfig?: boolean): Promise<boolean> => {
+        const configPath = globalConfig
+          ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+          : localGitConfigPath
+        let content = await fs.promises.readFile(configPath)
+        let lines = content
+          .toString()
+          .split('\n')
+          .filter(x => x)
+          .filter(x => !x.startsWith(key))
+        await fs.promises.writeFile(configPath, lines.join('\n'))
+        return true
+      }
+    ),
+    tryDisableAutomaticGarbageCollection: jest.fn(),
+    tryGetFetchUrl: jest.fn(),
+    tryReset: jest.fn()
+  }
+
+  settings = {
+    authToken: 'some auth token',
+    clean: true,
+    commit: '',
+    fetchDepth: 1,
+    lfs: false,
+    submodules: false,
+    nestedSubmodules: false,
+    persistCredentials: true,
+    ref: 'refs/heads/main',
+    repositoryName: 'my-repo',
+    repositoryOwner: 'my-org',
+    repositoryPath: '',
+    sshKey: sshPath ? 'some ssh private key' : '',
+    sshKnownHosts: '',
+    sshStrict: true,
+    workflowOrganizationId: 123456,
+    setSafeDirectory: true,
+    githubServerUrl: githubServerUrl
+  }
+}
+
+async function getActualSshKeyPath(): Promise<string> {
+  let actualTempFiles = (await fs.promises.readdir(runnerTemp))
+    .sort()
+    .map(x => path.join(runnerTemp, x))
+  if (actualTempFiles.length === 0) {
+    return ''
+  }
+
+  expect(actualTempFiles).toHaveLength(2)
+  expect(actualTempFiles[0].endsWith('_known_hosts')).toBeFalsy()
+  return actualTempFiles[0]
+}
+
+async function getActualSshKnownHostsPath(): Promise<string> {
+  let actualTempFiles = (await fs.promises.readdir(runnerTemp))
+    .sort()
+    .map(x => path.join(runnerTemp, x))
+  if (actualTempFiles.length === 0) {
+    return ''
+  }
+
+  expect(actualTempFiles).toHaveLength(2)
+  expect(actualTempFiles[1].endsWith('_known_hosts')).toBeTruthy()
+  expect(actualTempFiles[1].startsWith(actualTempFiles[0])).toBeTruthy()
+  return actualTempFiles[1]
+}

__test__/git-command-manager.test.ts

@@ -0,0 +1,80 @@
+import * as exec from '@actions/exec'
+import * as fshelper from '../lib/fs-helper'
+import * as commandManager from '../lib/git-command-manager'
+
+let git: commandManager.IGitCommandManager
+let mockExec = jest.fn()
+
+describe('git-auth-helper tests', () => {
+  beforeAll(async () => {})
+
+  beforeEach(async () => {
+    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
+    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+  })
+
+  afterAll(() => {})
+
+  it('branch list matches', async () => {
+    mockExec.mockImplementation((path, args, options) => {
+      console.log(args, options.listeners.stdout)
+
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+        return 0
+      }
+
+      if (args.includes('rev-parse')) {
+        options.listeners.stdline(Buffer.from('refs/heads/foo'))
+        options.listeners.stdline(Buffer.from('refs/heads/bar'))
+        return 0
+      }
+
+      return 1
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    const workingDirectory = 'test'
+    const lfs = false
+    git = await commandManager.createCommandManager(workingDirectory, lfs)
+
+    let branches = await git.branchList(false)
+
+    expect(branches).toHaveLength(2)
+    expect(branches.sort()).toEqual(['foo', 'bar'].sort())
+  })
+
+  it('ambiguous ref name output is captured', async () => {
+    mockExec.mockImplementation((path, args, options) => {
+      console.log(args, options.listeners.stdout)
+
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+        return 0
+      }
+
+      if (args.includes('rev-parse')) {
+        options.listeners.stdline(Buffer.from('refs/heads/foo'))
+        // If refs/tags/v1 and refs/heads/tags/v1 existed on this repository
+        options.listeners.errline(
+          Buffer.from("error: refname 'tags/v1' is ambiguous")
+        )
+        return 0
+      }
+
+      return 1
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+    const workingDirectory = 'test'
+    const lfs = false
+    git = await commandManager.createCommandManager(workingDirectory, lfs)
+
+    let branches = await git.branchList(false)
+
+    expect(branches).toHaveLength(1)
+    expect(branches.sort()).toEqual(['foo'].sort())
+  })
+})

__test__/git-directory-helper.test.ts

@@ -0,0 +1,441 @@
+import * as core from '@actions/core'
+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'
+
+const testWorkspace = path.join(__dirname, '_temp', 'git-directory-helper')
+let repositoryPath: string
+let repositoryUrl: string
+let clean: boolean
+let ref: string
+let git: IGitCommandManager
+
+describe('git-directory-helper tests', () => {
+  beforeAll(async () => {
+    // Clear test workspace
+    await io.rmRF(testWorkspace)
+  })
+
+  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())
+  })
+
+  afterEach(() => {
+    // Unregister mocks
+    jest.restoreAllMocks()
+  })
+
+  const cleansWhenCleanTrue = 'cleans when clean true'
+  it(cleansWhenCleanTrue, async () => {
+    // Arrange
+    await setup(cleansWhenCleanTrue)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.tryClean).toHaveBeenCalled()
+    expect(git.tryReset).toHaveBeenCalled()
+    expect(core.warning).not.toHaveBeenCalled()
+  })
+
+  const checkoutDetachWhenNotDetached = 'checkout detach when not detached'
+  it(checkoutDetachWhenNotDetached, async () => {
+    // Arrange
+    await setup(checkoutDetachWhenNotDetached)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.checkoutDetach).toHaveBeenCalled()
+  })
+
+  const doesNotCheckoutDetachWhenNotAlreadyDetached =
+    'does not checkout detach when already detached'
+  it(doesNotCheckoutDetachWhenNotAlreadyDetached, async () => {
+    // Arrange
+    await setup(doesNotCheckoutDetachWhenNotAlreadyDetached)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    const mockIsDetached = git.isDetached as jest.Mock<any, any>
+    mockIsDetached.mockImplementation(async () => {
+      return true
+    })
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.checkoutDetach).not.toHaveBeenCalled()
+  })
+
+  const doesNotCleanWhenCleanFalse = 'does not clean when clean false'
+  it(doesNotCleanWhenCleanFalse, async () => {
+    // Arrange
+    await setup(doesNotCleanWhenCleanFalse)
+    clean = false
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.isDetached).toHaveBeenCalled()
+    expect(git.branchList).toHaveBeenCalled()
+    expect(core.warning).not.toHaveBeenCalled()
+    expect(git.tryClean).not.toHaveBeenCalled()
+    expect(git.tryReset).not.toHaveBeenCalled()
+  })
+
+  const removesContentsWhenCleanFails = 'removes contents when clean fails'
+  it(removesContentsWhenCleanFails, async () => {
+    // Arrange
+    await setup(removesContentsWhenCleanFails)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    let mockTryClean = git.tryClean as jest.Mock<any, any>
+    mockTryClean.mockImplementation(async () => {
+      return false
+    })
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files).toHaveLength(0)
+    expect(git.tryClean).toHaveBeenCalled()
+    expect(core.warning).toHaveBeenCalled()
+    expect(git.tryReset).not.toHaveBeenCalled()
+  })
+
+  const removesContentsWhenDifferentRepositoryUrl =
+    'removes contents when different repository url'
+  it(removesContentsWhenDifferentRepositoryUrl, async () => {
+    // Arrange
+    await setup(removesContentsWhenDifferentRepositoryUrl)
+    clean = false
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    const differentRepositoryUrl =
+      'https://github.com/my-different-org/my-different-repo'
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      differentRepositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files).toHaveLength(0)
+    expect(core.warning).not.toHaveBeenCalled()
+    expect(git.isDetached).not.toHaveBeenCalled()
+  })
+
+  const removesContentsWhenNoGitDirectory =
+    'removes contents when no git directory'
+  it(removesContentsWhenNoGitDirectory, async () => {
+    // Arrange
+    await setup(removesContentsWhenNoGitDirectory)
+    clean = false
+    await io.rmRF(path.join(repositoryPath, '.git'))
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files).toHaveLength(0)
+    expect(core.warning).not.toHaveBeenCalled()
+    expect(git.isDetached).not.toHaveBeenCalled()
+  })
+
+  const removesContentsWhenResetFails = 'removes contents when reset fails'
+  it(removesContentsWhenResetFails, async () => {
+    // Arrange
+    await setup(removesContentsWhenResetFails)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    let mockTryReset = git.tryReset as jest.Mock<any, any>
+    mockTryReset.mockImplementation(async () => {
+      return false
+    })
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files).toHaveLength(0)
+    expect(git.tryClean).toHaveBeenCalled()
+    expect(git.tryReset).toHaveBeenCalled()
+    expect(core.warning).toHaveBeenCalled()
+  })
+
+  const removesContentsWhenUndefinedGitCommandManager =
+    'removes contents when undefined git command manager'
+  it(removesContentsWhenUndefinedGitCommandManager, async () => {
+    // Arrange
+    await setup(removesContentsWhenUndefinedGitCommandManager)
+    clean = false
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      undefined,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files).toHaveLength(0)
+    expect(core.warning).not.toHaveBeenCalled()
+  })
+
+  const removesLocalBranches = 'removes local branches'
+  it(removesLocalBranches, async () => {
+    // Arrange
+    await setup(removesLocalBranches)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    const mockBranchList = git.branchList as jest.Mock<any, any>
+    mockBranchList.mockImplementation(async (remote: boolean) => {
+      return remote ? [] : ['local-branch-1', 'local-branch-2']
+    })
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.branchDelete).toHaveBeenCalledWith(false, 'local-branch-1')
+    expect(git.branchDelete).toHaveBeenCalledWith(false, 'local-branch-2')
+  })
+
+  const removesLockFiles = 'removes lock files'
+  it(removesLockFiles, async () => {
+    // Arrange
+    await setup(removesLockFiles)
+    clean = false
+    await fs.promises.writeFile(
+      path.join(repositoryPath, '.git', 'index.lock'),
+      ''
+    )
+    await fs.promises.writeFile(
+      path.join(repositoryPath, '.git', 'shallow.lock'),
+      ''
+    )
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    let files = await fs.promises.readdir(path.join(repositoryPath, '.git'))
+    expect(files).toHaveLength(0)
+    files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.isDetached).toHaveBeenCalled()
+    expect(git.branchList).toHaveBeenCalled()
+    expect(core.warning).not.toHaveBeenCalled()
+    expect(git.tryClean).not.toHaveBeenCalled()
+    expect(git.tryReset).not.toHaveBeenCalled()
+  })
+
+  const removesAncestorRemoteBranch = 'removes ancestor remote branch'
+  it(removesAncestorRemoteBranch, async () => {
+    // Arrange
+    await setup(removesAncestorRemoteBranch)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    const mockBranchList = git.branchList as jest.Mock<any, any>
+    mockBranchList.mockImplementation(async (remote: boolean) => {
+      return remote ? ['origin/remote-branch-1', 'origin/remote-branch-2'] : []
+    })
+    ref = 'remote-branch-1/conflict'
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.branchDelete).toHaveBeenCalledTimes(1)
+    expect(git.branchDelete).toHaveBeenCalledWith(
+      true,
+      'origin/remote-branch-1'
+    )
+  })
+
+  const removesDescendantRemoteBranches = 'removes descendant remote branch'
+  it(removesDescendantRemoteBranches, async () => {
+    // Arrange
+    await setup(removesDescendantRemoteBranches)
+    await fs.promises.writeFile(path.join(repositoryPath, 'my-file'), '')
+    const mockBranchList = git.branchList as jest.Mock<any, any>
+    mockBranchList.mockImplementation(async (remote: boolean) => {
+      return remote
+        ? ['origin/remote-branch-1/conflict', 'origin/remote-branch-2']
+        : []
+    })
+    ref = 'remote-branch-1'
+
+    // Act
+    await gitDirectoryHelper.prepareExistingDirectory(
+      git,
+      repositoryPath,
+      repositoryUrl,
+      clean,
+      ref
+    )
+
+    // Assert
+    const files = await fs.promises.readdir(repositoryPath)
+    expect(files.sort()).toEqual(['.git', 'my-file'])
+    expect(git.branchDelete).toHaveBeenCalledTimes(1)
+    expect(git.branchDelete).toHaveBeenCalledWith(
+      true,
+      'origin/remote-branch-1/conflict'
+    )
+  })
+})
+
+async function setup(testName: string): Promise<void> {
+  testName = testName.replace(/[^a-zA-Z0-9_]+/g, '-')
+
+  // Repository directory
+  repositoryPath = path.join(testWorkspace, testName)
+  await fs.promises.mkdir(path.join(repositoryPath, '.git'), {recursive: true})
+
+  // Repository URL
+  repositoryUrl = 'https://github.com/my-org/my-repo'
+
+  // Clean
+  clean = true
+
+  // Ref
+  ref = ''
+
+  // Git command manager
+  git = {
+    branchDelete: jest.fn(),
+    branchExists: jest.fn(),
+    branchList: jest.fn(async () => {
+      return []
+    }),
+    checkout: jest.fn(),
+    checkoutDetach: jest.fn(),
+    config: jest.fn(),
+    configExists: jest.fn(),
+    fetch: jest.fn(),
+    getDefaultBranch: jest.fn(),
+    getWorkingDirectory: jest.fn(() => repositoryPath),
+    init: jest.fn(),
+    isDetached: jest.fn(),
+    lfsFetch: jest.fn(),
+    lfsInstall: jest.fn(),
+    log1: jest.fn(),
+    remoteAdd: jest.fn(),
+    removeEnvironmentVariable: jest.fn(),
+    revParse: jest.fn(),
+    setEnvironmentVariable: jest.fn(),
+    shaExists: jest.fn(),
+    submoduleForeach: jest.fn(),
+    submoduleSync: jest.fn(),
+    submoduleUpdate: jest.fn(),
+    tagExists: jest.fn(),
+    tryClean: jest.fn(async () => {
+      return true
+    }),
+    tryConfigUnset: jest.fn(),
+    tryDisableAutomaticGarbageCollection: jest.fn(),
+    tryGetFetchUrl: jest.fn(async () => {
+      // Sanity check - this function shouldn't be called when the .git directory doesn't exist
+      await fs.promises.stat(path.join(repositoryPath, '.git'))
+      return repositoryUrl
+    }),
+    tryReset: jest.fn(async () => {
+      return true
+    })
+  }
+}

__test__/input-helper.test.ts

@@ -1,47 +1,55 @@
-import * as assert from 'assert'
+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 * as path from 'path'
-import {ISourceSettings} from '../lib/git-source-provider'
+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')
 
-// Late bind
-let inputHelper: any
-
-// Mock @actions/core
+// Inputs for mock @actions/core
 let inputs = {} as any
-const mockCore = jest.genMockFromModule('@actions/core') as any
-mockCore.getInput = (name: string) => {
-  return inputs[name]
-}
 
-// Mock @actions/github
-const mockGitHub = jest.genMockFromModule('@actions/github') as any
-mockGitHub.context = {
-  repo: {
-    owner: 'some-owner',
-    repo: 'some-repo'
-  },
-  ref: 'refs/heads/some-ref',
-  sha: '1234567890123456789012345678901234567890'
-}
-
-// Mock ./fs-helper
-const mockFSHelper = jest.genMockFromModule('../lib/fs-helper') as any
-mockFSHelper.directoryExistsSync = (path: string) => path == gitHubWorkspace
+// Shallow clone original @actions/github context
+let originalContext = {...github.context}
 
 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
-
-    // Mocks
-    jest.setMock('@actions/core', mockCore)
-    jest.setMock('@actions/github', mockGitHub)
-    jest.setMock('../lib/fs-helper', mockFSHelper)
-
-    // Now import
-    inputHelper = require('../lib/input-helper')
   })
 
   beforeEach(() => {
@@ -50,18 +58,22 @@ describe('input-helper tests', () => {
   })
 
   afterAll(() => {
-    // Reset GitHub workspace
+    // Restore GitHub workspace
     delete process.env['GITHUB_WORKSPACE']
     if (originalGitHubWorkspace) {
       process.env['GITHUB_WORKSPACE'] = originalGitHubWorkspace
     }
 
-    // Reset modules
-    jest.resetModules()
+    // Restore @actions/github context
+    github.context.ref = originalContext.ref
+    github.context.sha = originalContext.sha
+
+    // Restore
+    jest.restoreAllMocks()
   })
 
-  it('sets defaults', () => {
-    const settings: ISourceSettings = inputHelper.getInputs()
+  it('sets defaults', async () => {
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings).toBeTruthy()
     expect(settings.authToken).toBeFalsy()
     expect(settings.clean).toBe(true)
@@ -73,48 +85,58 @@ describe('input-helper tests', () => {
     expect(settings.repositoryName).toBe('some-repo')
     expect(settings.repositoryOwner).toBe('some-owner')
     expect(settings.repositoryPath).toBe(gitHubWorkspace)
+    expect(settings.setSafeDirectory).toBe(true)
   })
 
-  it('requires qualified repo', () => {
+  it('qualifies ref', async () => {
+    let originalRef = github.context.ref
+    try {
+      github.context.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
+    }
+  })
+
+  it('requires qualified repo', async () => {
     inputs.repository = 'some-unqualified-repo'
-    assert.throws(() => {
-      inputHelper.getInputs()
-    }, /Invalid repository 'some-unqualified-repo'/)
+    try {
+      await inputHelper.getInputs()
+      throw 'should not reach here'
+    } catch (err) {
+      expect(`(${(err as any).message}`).toMatch(
+        "Invalid repository 'some-unqualified-repo'"
+      )
+    }
   })
 
-  it('roots path', () => {
+  it('roots path', async () => {
     inputs.path = 'some-directory/some-subdirectory'
-    const settings: ISourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.repositoryPath).toBe(
       path.join(gitHubWorkspace, 'some-directory', 'some-subdirectory')
     )
   })
 
-  it('sets correct default ref/sha for other repo', () => {
-    inputs.repository = 'some-owner/some-other-repo'
-    const settings: ISourceSettings = inputHelper.getInputs()
-    expect(settings.ref).toBe('refs/heads/master')
-    expect(settings.commit).toBeFalsy()
-  })
-
-  it('sets ref to empty when explicit sha', () => {
+  it('sets ref to empty when explicit sha', async () => {
     inputs.ref = '1111111111222222222233333333334444444444'
-    const settings: ISourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.ref).toBeFalsy()
     expect(settings.commit).toBe('1111111111222222222233333333334444444444')
   })
 
-  it('sets sha to empty when explicit ref', () => {
+  it('sets sha to empty when explicit ref', async () => {
     inputs.ref = 'refs/heads/some-other-ref'
-    const settings: ISourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.ref).toBe('refs/heads/some-other-ref')
     expect(settings.commit).toBeFalsy()
   })
 
-  it('gives good error message for submodules input', () => {
-    inputs.submodules = 'true'
-    assert.throws(() => {
-      inputHelper.getInputs()
-    }, /The input 'submodules' is not supported/)
+  it('sets workflow organization ID', async () => {
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.workflowOrganizationId).toBe(123456)
   })
 })

__test__/override-git-version.cmd

@@ -0,0 +1,6 @@
+
+mkdir override-git-version
+cd override-git-version
+echo @echo override git version 1.2.3 > git.cmd
+echo "%CD%" >> $GITHUB_PATH
+cd ..

__test__/override-git-version.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+mkdir override-git-version
+cd override-git-version
+echo "#!/bin/sh" > git
+echo "echo override git version 1.2.3" >> git
+chmod +x git
+echo "$(pwd)" >> $GITHUB_PATH
+cd ..

__test__/ref-helper.test.ts

@@ -16,7 +16,7 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, 'refs/heads/my/branch', commit)
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe('Arg git cannot be empty')
+      expect((err as any)?.message).toBe('Arg git cannot be empty')
     }
   })
 
@@ -25,7 +25,9 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, '', '')
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe('Args ref and commit cannot both be empty')
+      expect((err as any)?.message).toBe(
+        'Args ref and commit cannot both be empty'
+      )
     }
   })
 
@@ -102,7 +104,7 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, 'my-ref', '')
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe(
+      expect((err as any)?.message).toBe(
         "A branch or tag with the name 'my-ref' could not be found"
       )
     }

__test__/retry-helper.test.ts

@@ -1,18 +1,17 @@
-const mockCore = jest.genMockFromModule('@actions/core') as any
-mockCore.info = (message: string) => {
-  info.push(message)
-}
+import * as core from '@actions/core'
+import {RetryHelper} from '../lib/retry-helper'
+
 let info: string[]
 let retryHelper: any
 
 describe('retry-helper tests', () => {
   beforeAll(() => {
-    // Mocks
-    jest.setMock('@actions/core', mockCore)
+    // Mock @actions/core info()
+    jest.spyOn(core, 'info').mockImplementation((message: string) => {
+      info.push(message)
+    })
 
-    // Now import
-    const retryHelperModule = require('../lib/retry-helper')
-    retryHelper = new retryHelperModule.RetryHelper(3, 0, 0)
+    retryHelper = new RetryHelper(3, 0, 0)
   })
 
   beforeEach(() => {
@@ -21,8 +20,8 @@ describe('retry-helper tests', () => {
   })
 
   afterAll(() => {
-    // Reset modules
-    jest.resetModules()
+    // Restore
+    jest.restoreAllMocks()
   })
 
   it('first attempt succeeds', async () => {
@@ -75,7 +74,7 @@ describe('retry-helper tests', () => {
         throw new Error(`some error ${++attempts}`)
       })
     } catch (err) {
-      error = err
+      error = err as Error
     }
     expect(error.message).toBe('some error 3')
     expect(attempts).toBe(3)

__test__/verify-basic.sh

@@ -20,5 +20,5 @@ else
 
   # Verify auth token
   cd basic
-  git fetch --no-tags --depth=1 origin +refs/heads/master:refs/remotes/origin/master
+  git fetch --no-tags --depth=1 origin +refs/heads/main:refs/remotes/origin/main
 fi

__test__/verify-no-unstaged-changes.sh

@@ -12,6 +12,6 @@ if [[ "$(git status --porcelain)" != "" ]]; then
     echo ----------------------------------------
     echo Troubleshooting
     echo ----------------------------------------
-    echo "::error::Unstaged changes detected. Locally try running: git clean -ffdx && npm ci && npm run all"
+    echo "::error::Unstaged changes detected. Locally try running: git clean -ffdx && npm ci && npm run format && npm run build"
     exit 1
 fi

__test__/verify-submodules-false.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+if [ ! -f "./submodules-false/regular-file.txt" ]; then
+    echo "Expected regular file does not exist"
+    exit 1
+fi
+
+if [ -f "./submodules-false/submodule-level-1/submodule-file.txt" ]; then
+    echo "Unexpected submodule file exists"
+    exit 1
+fi

__test__/verify-submodules-not-checked-out.sh

@@ -1,11 +0,0 @@
-#!/bin/bash
-
-if [ ! -f "./submodules-not-checked-out/regular-file.txt" ]; then
-    echo "Expected regular file does not exist"
-    exit 1
-fi
-
-if [ -f "./submodules-not-checked-out/submodule-level-1/submodule-file.txt" ]; then
-    echo "Unexpected submodule file exists"
-    exit 1
-fi

__test__/verify-submodules-recursive.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+if [ ! -f "./submodules-recursive/regular-file.txt" ]; then
+    echo "Expected regular file does not exist"
+    exit 1
+fi
+
+if [ ! -f "./submodules-recursive/submodule-level-1/submodule-file.txt" ]; then
+    echo "Expected submodule file does not exist"
+    exit 1
+fi
+
+if [ ! -f "./submodules-recursive/submodule-level-1/submodule-level-2/nested-submodule-file.txt" ]; then
+    echo "Expected nested submodule file does not exists"
+    exit 1
+fi
+
+echo "Testing persisted credential"
+pushd ./submodules-recursive/submodule-level-1/submodule-level-2
+git config --local --name-only --get-regexp http.+extraheader && git fetch
+if [ "$?" != "0" ]; then
+    echo "Failed to validate persisted credential"
+    popd
+    exit 1
+fi
+popd

__test__/verify-submodules-true.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+if [ ! -f "./submodules-true/regular-file.txt" ]; then
+    echo "Expected regular file does not exist"
+    exit 1
+fi
+
+if [ ! -f "./submodules-true/submodule-level-1/submodule-file.txt" ]; then
+    echo "Expected submodule file does not exist"
+    exit 1
+fi
+
+if [ -f "./submodules-true/submodule-level-1/submodule-level-2/nested-submodule-file.txt" ]; then
+    echo "Unexpected nested submodule file exists"
+    exit 1
+fi
+
+echo "Testing persisted credential"
+pushd ./submodules-true/submodule-level-1
+git config --local --name-only --get-regexp http.+extraheader && git fetch
+if [ "$?" != "0" ]; then
+    echo "Failed to validate persisted credential"
+    popd
+    exit 1
+fi
+popd

action.yml

@@ -1,6 +1,6 @@
 name: 'Checkout'
 description: 'Checkout a Git repository at a particular version'
-inputs: 
+inputs:
   repository:
     description: 'Repository name with owner. For example, actions/checkout'
     default: ${{ github.repository }}
@@ -8,15 +8,45 @@ inputs:
     description: >
       The branch, tag or SHA to checkout. When checking out the repository that
       triggered a workflow, this defaults to the reference or SHA for that
-      event.  Otherwise, defaults to `master`.
+      event.  Otherwise, uses the default branch.
   token:
     description: >
-      Auth token used to fetch the repository. The token is stored in the local
-      git config, which enables your scripts to run authenticated git commands.
-      The post-job step removes the token from the git config.
+      Personal access token (PAT) used to fetch the repository. The PAT is configured
+      with the local git config, which enables your scripts to run authenticated git
+      commands. The post-job step removes the PAT.
+
+
+      We recommend using a service account with the least permissions necessary.
+      Also when generating a new PAT, select the least scopes necessary.
+
+
+      [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
     default: ${{ github.token }}
+  ssh-key:
+    description: >
+      SSH key used to fetch the repository. The SSH key is configured with the local
+      git config, which enables your scripts to run authenticated git commands.
+      The post-job step removes the SSH key.
+
+
+      We recommend using a service account with the least permissions necessary.
+
+
+      [Learn more about creating and using
+      encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+  ssh-known-hosts:
+    description: >
+      Known hosts in addition to the user and global host key database. The public
+      SSH keys for a host may be obtained using the utility `ssh-keyscan`. For example,
+      `ssh-keyscan github.com`. The public key for github.com is always implicitly added.
+  ssh-strict:
+    description: >
+      Whether to perform strict host key checking. When true, adds the options `StrictHostKeyChecking=yes`
+      and `CheckHostIP=no` to the SSH command line. Use the input `ssh-known-hosts` to
+      configure additional hosts.
+    default: true
   persist-credentials:
-    description: 'Whether to persist the token in the git config'
+    description: 'Whether to configure the token or SSH key with the local git config'
     default: true
   path:
     description: 'Relative path under $GITHUB_WORKSPACE to place the repository'
@@ -24,12 +54,27 @@ inputs:
     description: 'Whether to execute `git clean -ffdx && git reset --hard HEAD` before fetching'
     default: true
   fetch-depth:
-    description: 'Number of commits to fetch. 0 indicates all history.'
+    description: 'Number of commits to fetch. 0 indicates all history for all branches and tags.'
     default: 1
   lfs:
     description: 'Whether to download Git-LFS files'
     default: false
+  submodules:
+    description: >
+      Whether to checkout submodules: `true` to checkout submodules or `recursive` to
+      recursively checkout submodules.
+
+
+      When the `ssh-key` input is not provided, SSH URLs beginning with `git@github.com:` are
+      converted to HTTPS.
+    default: false
+  set-safe-directory:
+    description: Add repository path as safe.directory for Git global config by running `git config --global --add safe.directory <path>`
+    default: true
+  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
 runs:
-  using: node12
+  using: node16
   main: dist/index.js
   post: dist/index.js

adrs/0153-checkout-v2.md

@@ -0,0 +1,290 @@
+# ADR 0153: Checkout v2
+
+**Date**: 2019-10-21
+
+**Status**: Accepted
+
+## Context
+
+This ADR details the behavior for `actions/checkout@v2`.
+
+The new action will be written in typescript. We are moving away from runner-plugin actions.
+
+We want to take this opportunity to make behavioral changes, from v1. This document is scoped to those differences.
+
+## Decision
+
+### Inputs
+
+```yaml
+  repository:
+    description: 'Repository name with owner. For example, actions/checkout'
+    default: ${{ github.repository }}
+  ref:
+    description: >
+      The branch, tag or SHA to checkout. When checking out the repository that
+      triggered a workflow, this defaults to the reference or SHA for that
+      event.  Otherwise, uses the default branch.
+  token:
+    description: >
+      Personal access token (PAT) used to fetch the repository. The PAT is configured
+      with the local git config, which enables your scripts to run authenticated git
+      commands. The post-job step removes the PAT.
+
+
+      We recommend using a service account with the least permissions necessary.
+      Also when generating a new PAT, select the least scopes necessary.
+
+
+      [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+    default: ${{ github.token }}
+  ssh-key:
+    description: >
+      SSH key used to fetch the repository. The SSH key is configured with the local
+      git config, which enables your scripts to run authenticated git commands.
+      The post-job step removes the SSH key.
+
+
+      We recommend using a service account with the least permissions necessary.
+
+
+      [Learn more about creating and using
+      encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+  ssh-known-hosts:
+    description: >
+      Known hosts in addition to the user and global host key database. The public
+      SSH keys for a host may be obtained using the utility `ssh-keyscan`. For example,
+      `ssh-keyscan github.com`. The public key for github.com is always implicitly added.
+  ssh-strict:
+    description: >
+      Whether to perform strict host key checking. When true, adds the options `StrictHostKeyChecking=yes`
+      and `CheckHostIP=no` to the SSH command line. Use the input `ssh-known-hosts` to
+      configure additional hosts.
+    default: true
+  persist-credentials:
+    description: 'Whether to configure the token or SSH key with the local git config'
+    default: true
+  path:
+    description: 'Relative path under $GITHUB_WORKSPACE to place the repository'
+  clean:
+    description: 'Whether to execute `git clean -ffdx && git reset --hard HEAD` before fetching'
+    default: true
+  fetch-depth:
+    description: 'Number of commits to fetch. 0 indicates all history for all tags and branches.'
+    default: 1
+  lfs:
+    description: 'Whether to download Git-LFS files'
+    default: false
+  submodules:
+    description: >
+      Whether to checkout submodules: `true` to checkout submodules or `recursive` to
+      recursively checkout submodules.
+
+
+      When the `ssh-key` input is not provided, SSH URLs beginning with `git@github.com:` are
+      converted to HTTPS.
+    default: false
+```
+
+Note:
+- SSH support is new
+- `persist-credentials` is new
+- `path` behavior is different (refer [below](#path) for details)
+
+### Fallback to GitHub API
+
+When a sufficient version of git is not in the PATH, fallback to the [web API](https://developer.github.com/v3/repos/contents/#get-archive-link) to download a tarball/zipball.
+
+Note:
+- LFS files are not included in the archive. Therefore fail if LFS is set to true.
+- Submodules are also not included in the archive.
+
+### Persist credentials
+
+The credentials will be persisted on disk. This will allow users to script authenticated git commands, like `git fetch`.
+
+A post script will remove the credentials (cleanup for self-hosted).
+
+Users may opt-out by specifying `persist-credentials: false`
+
+Note:
+- Users scripting `git commit` may need to set the username and email. The service does not provide any reasonable default value. Users can add `git config user.name <NAME>` and `git config user.email <EMAIL>`. We will document this guidance.
+
+#### PAT
+
+When using the `${{github.token}}` or a PAT, the token will be persisted in the local git config. The config key `http.https://github.com/.extraheader` enables an auth header to be specified on all authenticated commands `AUTHORIZATION: basic <BASE64_U:P>`.
+
+Note:
+- The auth header is scoped to all of github `http.https://github.com/.extraheader`
+  - Additional public remotes also just work.
+  - If users want to authenticate to an additional private remote, they should provide the `token` input.
+
+#### SSH key
+
+The SSH key will be written to disk under the `$RUNNER_TEMP` directory. The SSH key will
+be removed by the action's post-job hook. Additionally, RUNNER_TEMP is cleared by the
+runner between jobs.
+
+The SSH key must be written with strict file permissions. The SSH client requires the file
+to be read/write for the user, and not accessible by others.
+
+The user host key database (`~/.ssh/known_hosts`) will be copied to a unique file under
+`$RUNNER_TEMP`. And values from the input `ssh-known-hosts` will be added to the file.
+
+The SSH command will be overridden for the local git config:
+
+```sh
+git config core.sshCommand 'ssh -i "$RUNNER_TEMP/path-to-ssh-key" -o StrictHostKeyChecking=yes -o CheckHostIP=no -o "UserKnownHostsFile=$RUNNER_TEMP/path-to-known-hosts"'
+```
+
+When the input `ssh-strict` is set to `false`, the options `CheckHostIP` and `StrictHostKeyChecking` will not be overridden.
+
+Note:
+- When `ssh-strict` is set to `true` (default), the SSH option `CheckHostIP` can safely be disabled.
+  Strict host checking verifies the server's public key. Therefore, IP verification is unnecessary
+  and noisy. For example:
+  > Warning: Permanently added the RSA host key for IP address '140.82.113.4' to the list of known hosts.
+- Since GIT_SSH_COMMAND overrides core.sshCommand, temporarily set the env var when fetching the repo. When creds
+  are persisted, core.sshCommand is leveraged to avoid multiple checkout steps stomping over each other.
+- Modify actions/runner to mount RUNNER_TEMP to enable scripting authenticated git commands from a container action.
+- Refer [here](https://linux.die.net/man/5/ssh_config) for SSH config details.
+
+### Fetch behavior
+
+Fetch only the SHA being built and set depth=1. This significantly reduces the fetch time for large repos.
+
+If a SHA isn't available (e.g. multi repo), then fetch only the specified ref with depth=1.
+
+The input `fetch-depth` can be used to control the depth.
+
+Note:
+- Fetching a single commit is supported by Git wire protocol version 2. The git client uses protocol version 0 by default. The desired protocol version can be overridden in the git config or on the fetch command line invocation (`-c protocol.version=2`). We will override on the fetch command line, for transparency.
+- Git client version 2.18+ (released June 2018) is required for wire protocol version 2.
+
+### Checkout behavior
+
+For CI, checkout will create a local ref with the upstream set. This allows users to script git as they normally would.
+
+For PR, continue to checkout detached head. The PR branch is special - the branch and merge commit are created by the server. It doesn't match a users' local workflow.
+
+Note:
+- Consider deleting all local refs during cleanup if that helps avoid collisions. More testing required.
+
+### Path
+
+For the mainline scenario, the disk-layout behavior remains the same.
+
+Remember, given the repo `johndoe/foo`, the mainline disk layout looks like:
+
+```
+GITHUB_WORKSPACE=/home/runner/work/foo/foo
+RUNNER_WORKSPACE=/home/runner/work/foo
+```
+
+V2 introduces a new contraint on the checkout path. The location must now be under `github.workspace`. Whereas the checkout@v1 constraint was one level up, under `runner.workspace`.
+
+V2 no longer changes `github.workspace` to follow wherever the self repo is checked-out.
+
+These behavioral changes align better with container actions. The [documented filesystem contract](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/virtual-environments-for-github-hosted-runners#docker-container-filesystem) is:
+
+- `/github/home`
+- `/github/workspace` - Note: GitHub Actions must be run by the default Docker user (root). Ensure your Dockerfile does not set the USER instruction, otherwise you will not be able to access `GITHUB_WORKSPACE`.
+- `/github/workflow`
+
+Note:
+- The tracking config will not be updated to reflect the path of the workflow repo.
+- Any existing workflow repo will not be moved when the checkout path changes. In fact some customers want to checkout the workflow repo twice, side by side against different branches.
+- Actions that need to operate only against the root of the self repo, should expose a `path` input.
+
+#### Default value for `path` input
+
+The `path` input will default to `./` which is rooted against `github.workspace`.
+
+This default fits the mainline scenario well: single checkout
+
+For multi-checkout, users must specify the `path` input for at least one of the repositories.
+
+Note:
+- An alternative is for the self repo to default to `./` and other repos default to `<REPO_NAME>`. However nested layout is an atypical git layout and therefore is not a good default. Users should supply the path info.
+
+#### Example - Nested layout
+
+The following example checks-out two repositories and creates a nested layout.
+
+```yaml
+# Self repo - Checkout to $GITHUB_WORKSPACE
+- uses: checkout@v2
+
+# Other repo - Checkout to $GITHUB_WORKSPACE/myscripts
+- uses: checkout@v2
+  with:
+    repository: myorg/myscripts
+    path: myscripts
+```
+
+#### Example - Side by side layout
+
+The following example checks-out two repositories and creates a side-by-side layout.
+
+```yaml
+# Self repo - Checkout to $GITHUB_WORKSPACE/foo
+- uses: checkout@v2
+  with:
+    path: foo
+
+# Other repo - Checkout to $GITHUB_WORKSPACE/myscripts
+- uses: checkout@v2
+  with:
+    repository: myorg/myscripts
+    path: myscripts
+```
+
+#### Path impact to problem matchers
+
+Problem matchers associate the source files with annotations.
+
+Today the runner verifies the source file is under the `github.workspace`. Otherwise the source file property is dropped.
+
+Multi-checkout complicates the matter. However even today submodules may cause this heuristic to be inaccurate.
+
+A better solution is:
+
+Given a source file path, walk up the directories until the first `.git/config` is found. Check if it matches the self repo (`url = https://github.com/OWNER/REPO`). If not, drop the source file path.
+
+### Submodules
+
+With both PAT and SSH key support, we should be able to provide frictionless support for
+submodules scenarios: recursive, non-recursive, relative submodule paths.
+
+When fetching submodules, follow the `fetch-depth` settings.
+
+Also when fetching submodules, if the `ssh-key` input is not provided then convert SSH URLs to HTTPS: `-c url."https://github.com/".insteadOf "git@github.com:"`
+
+Credentials will be persisted in the submodules local git config too.
+
+### Port to typescript
+
+The checkout action should be a typescript action on the GitHub graph, for the following reasons:
+- Enables customers to fork the checkout repo and modify
+- Serves as an example for customers
+- Demystifies the checkout action manifest
+- Simplifies the runner
+- Reduce the amount of runner code to port (if we ever do)
+
+Note:
+- This means job-container images will need git in the PATH, for checkout.
+
+### Branching strategy and release tags
+
+- Create a servicing branch for V1: `releases/v1`
+- Merge the changes into the default branch
+- Release using a new tag `preview`
+- When stable, release using a new tag `v2`
+
+## Consequences
+
+- Update the checkout action and readme
+- Update samples to consume `actions/checkout@v2`
+- Job containers now require git in the PATH for checkout, otherwise fallback to REST API
+- Minimum git version 2.18
+- Update problem matcher logic regarding source file verification (runner)