GitHub Workflow运行Prettier后提交PR失败，寻求技术指导

问题描述 #

我想实现一个GitHub Workflow，自动对Pull Request（PR）中新增/修改的文件执行Prettier代码格式化，并将格式化后的修改提交回PR。已编写Workflow配置，但提交步骤报错，附上代码及错误截图求助。

Workflow代码 #

name: Pull Request Workflow
on:
    pull_request:
        types: [opened, reopened, edited, synchronize]
jobs:
    lint-analyse-code:
        name: Lint & Analyse Code
        runs-on: ubuntu-latest
        steps:
            - name: Step 1 - Checkout Repository
              uses: actions/checkout@v3
            
            - name: Step 2 - Setup GIT 
              run: |
                  echo "BRANCHES"
                  git branch -v
                  echo "REMOTES"
                  git remote -v
                  echo "GITHUB_REF is $GITHUB_REF"
                  echo "GITHUB_HEAD_REF is $GITHUB_HEAD_REF"
                  echo "GITHUB_BASE_REF is $GITHUB_BASE_REF"
                  git config advice.ignoredHook false

            - name: Step 3 - Setup Node.js
              uses: actions/setup-node@v3

            - name: Step 4 - Install NPM Dependencies
              run: npm install

            - name: Step 5 - Get Changed Files
              id: changed-files
              uses: tj-actions/changed-files@v29.0.7 
              with:
                since_last_remote_commit: true

            - name: Step 6 - Prettier
              run: npm run prettier-npx ${{ steps.changed-files.outputs.all_changed_files }}

            - name: Step 7 - Commit Changes
              run: | 
                echo HEAD:$GITHUB_HEAD_REF
                git config user.email "devops@blahblah.co.za" 
                git config user.name "DevOps"
                git add .
                git commit -m "Automatically Applied Prettier [skip actions]" || echo "Nothing to push"
                git push origin HEAD:$GITHUB_HEAD_REF

错误截图 #

解决方法 #

1. 核心问题分析 #

报错原因主要是Git权限不足和分支checkout方式不正确：

• 默认的actions/checkout@v3未指定PR分支，且默认凭证无推送权限
• 文件名含空格时，Prettier命令可能无法正确处理

2. 分步修复 #

（1）修正Checkout步骤

直接checkout PR的目标分支，禁用默认凭证并拉取完整历史：

- name: Checkout Repository
  uses: actions/checkout@v3
  with:
    ref: ${{ github.head_ref }}  # 拉取PR的源分支
    persist-credentials: false   # 避免默认凭证干扰
    fetch-depth: 0               # 拉取完整仓库历史

（2）配置Git推送凭证

添加凭证配置，使用仓库的GITHUB_TOKEN（同仓库PR适用）：

- name: Configure Git Credentials
  run: |
    git config --global credential.helper store
    echo "https://${{ secrets.GITHUB_TOKEN }}:@github.com" > ~/.git-credentials

如果是处理fork过来的PR，需在仓库Secrets中添加带repo权限的个人访问令牌（PAT），并将上述代码中的${{ secrets.GITHUB_TOKEN }}替换为${{ secrets.PAT }}。

（3）修复Prettier命令

循环处理每个变更文件，避免文件名含空格导致的错误：

- name: Run Prettier on Changed Files
  run: |
    for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
      if [ -f "$file" ]; then
        npx prettier --write "$file"
      fi
    done

3. 完整修复后的Workflow #

name: Pull Request Workflow
on:
    pull_request:
        types: [opened, reopened, edited, synchronize]
jobs:
    lint-analyse-code:
        name: Lint & Analyse Code
        runs-on: ubuntu-latest
        steps:
            - name: Checkout Repository
              uses: actions/checkout@v3
              with:
                ref: ${{ github.head_ref }}
                persist-credentials: false
                fetch-depth: 0
            
            - name: Setup Git
              run: |
                git config user.email "devops@blahblah.co.za"
                git config user.name "DevOps"
                git config advice.ignoredHook false

            - name: Setup Node.js
              uses: actions/setup-node@v3
              with:
                node-version: 20  # 指定Node版本，避免环境差异

            - name: Install NPM Dependencies
              run: npm install

            - name: Get Changed Files
              id: changed-files
              uses: tj-actions/changed-files@v29.0.7 
              with:
                since_last_remote_commit: true

            - name: Run Prettier on Changed Files
              run: |
                for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
                  if [ -f "$file" ]; then
                    npx prettier --write "$file"
                  fi
                done

            - name: Configure Git Credentials
              run: |
                git config --global credential.helper store
                echo "https://${{ secrets.GITHUB_TOKEN }}:@github.com" > ~/.git-credentials

            - name: Commit and Push Changes
              run: |
                git add .
                git commit -m "Automatically Applied Prettier [skip actions]" || echo "No changes to commit"
                git push origin HEAD:${{ github.head_ref }}

额外注意事项 #

• 提交消息中的[skip actions]可避免触发Workflow循环执行
• 处理fork的PR时，必须使用个人访问令牌，默认GITHUB_TOKEN无推送权限
• 指定Node.js版本可减少依赖安装的环境差异问题

内容的提问来源于stack exchange，提问作者Peter Guest