Dev Gh Actions Doc Auto Merge

---
name: dev-gh-actions-doc-auto-merge
description: "Create a GitHub Actions workflow that auto-merges a production branch into a documentation branch. Use when: (1) Setting up auto-sync from production to doc branch, (2) User mentions 'doc auto merge', 'auto sync docs', 'document branch sync', (3) User wants docs to stay up-to-date with production automatically."
---

# Doc Branch Auto-Merge GitHub Actions Workflow

Create a GitHub Actions workflow that automatically merges a production branch into a documentation deploy branch, keeping docs up-to-date without manual sync.

## Workflow

### 1. Confirm branch names

Ask the user to confirm (use AskUserQuestion):

- **Document branch**: The branch that triggers doc site deployment (default: `doc`)
- **Production branch**: The source-of-truth branch to merge from (default: `main`)

### 2. Check for existing workflow

Look for existing sync workflows in `.github/workflows/` to avoid duplicates.

### 3. Create the workflow file

Create `.github/workflows/sync-<production>-to-<doc>.yml`:

```yaml
name: Sync <production> to <doc> branch

# <production>ブランチへのpush時に<doc>ブランチへ自動マージ
# ドキュメントサイトが常に最新の<production>の内容を反映するようにする
on:
  push:
    branches: [<production>]

permissions:
  contents: write

jobs:
  sync:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          ref: <doc>
          fetch-depth: 0

      - name: Merge <production> into <doc>
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git merge origin/<production> --no-edit

      - name: Push
        run: git push origin <doc>
```

Replace `<production>` and `<doc>` with the confirmed branch names.

### 4. Remind the user

After creating the workflow file, remind:

- This workflow must exist on the **production branch** (the `on.push.branches` target) for GitHub Actions to pick it up
- If currently on a different branch, the file needs to be merged into the production branch first
- If merge conflicts occur between the two branches, the Action will fail and notify via GitHub Actions tab — a human resolves manually