GitHub Actions自动生成Dev转Main PR显示历史提交的问题求助

分支流程 #

• 功能/问题开发基于issue_branch，从dev分支创建
• 开发测试完成后，提交issue_branch到dev的PR，人工审核后合并
• 当该PR合并到dev时，触发create-main-pr任务，自动创建dev到main的PR

问题 #

自动生成的main分支PR会显示所有过往版本的提交历史，哪怕只在issue_branch做了一处小改动（单个提交）也会出现这个问题，并非仅在 squash 合并时发生。

预期结果 #

该PR应仅展示上次发布以来的新提交。已知问题和SHA有关，但不清楚修复方案。

当前使用的GitHub Actions代码 #

create-main-pr:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    if: |
      github.event_name == 'pull_request' &&
      github.event.action == 'closed' &&
      github.event.pull_request.merged == true &&
      github.event.pull_request.base.ref == 'dev'
    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.MY_SECRET }}

      - name: Create Pull Request
        id: create-pr
        uses: peter-evans/create-pull-request@v5
        with:
          token: ${{ secrets.MY_SECRET }}
          commit-message: "chore: promote dev to main"
          branch: promote-dev-to-main
          delete-branch: true
          title: "🚀 Promote Dev to Main"
          body: |
            ## Automated Promotion PR
            
            This PR was automatically created to promote changes from `dev` to `main`.
            
            ### ✅ Pre-merge Checklist
            - [ ] Changes have been reviewed
            - [ ] Tests are passing
            - [ ] Documentation is up to date
            
            ### 📝 Notes
            - This PR was automatically generated
            - Please review carefully before merging
            - Manual merge required
          labels: |
            automated
            promotion
          base: main
          branch-suffix: timestamp

已尝试的操作 #

发布完成后同步main与dev分支，创建issue_branch并做一处小改动，合并至dev后触发任务生成PR，但问题依旧。

修复方案 #

1. 确保发布后dev与main完全同步（根源性解决） #

每次将main发布后，必须强制将dev重置为main的状态，避免历史分叉：

# 可在发布流程的Action中执行此逻辑
git checkout dev
git fetch origin main
git reset --hard origin/main
git push origin dev --force

这样后续从dev开出的issue_branch提交历史会完全基于最新的main，合并到dev后，dev和main的历史只会有新提交的差异，不会出现分叉。

2. 修改自动PR的创建逻辑，以main为基准创建临时分支 #

当前Action直接用dev分支创建PR到main，若历史分叉会显示所有差异提交。改成先基于main创建临时分支，再合并dev的变更，PR差异就只会是新提交：

create-main-pr:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    if: |
      github.event_name == 'pull_request' &&
      github.event.action == 'closed' &&
      github.event.pull_request.merged == true &&
      github.event.pull_request.base.ref == 'dev'
    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.MY_SECRET }}

      - name: Prepare Promotion Branch
        run: |
          git checkout main
          git pull origin main
          git checkout -b promote-dev-to-main
          git merge origin/dev --no-ff --no-edit
          git push origin promote-dev-to-main

      - name: Create Pull Request
        id: create-pr
        uses: peter-evans/create-pull-request@v5
        with:
          token: ${{ secrets.MY_SECRET }}
          commit-message: "chore: promote dev to main"
          branch: promote-dev-to-main
          delete-branch: true
          title: "🚀 Promote Dev to Main"
          body: |
            ## Automated Promotion PR
            
            This PR was automatically created to promote changes from `dev` to `main`.
            
            ### ✅ Pre-merge Checklist
            - [ ] Changes have been reviewed
            - [ ] Tests are passing
            - [ ] Documentation is up to date
            
            ### 📝 Notes
            - This PR was automatically generated
            - Please review carefully before merging
            - Manual merge required
          labels: |
            automated
            promotion
          base: main
          branch-suffix: timestamp

3. 统一合并方式，避免历史混乱 #

确保所有合并到dev的PR使用保留完整提交历史的合并方式（非squash、非rebase），这样dev的历史是线性的，和main同步后不会出现SHA不一致的分叉问题。

内容的提问来源于stack exchange，提问作者mywn9