Git Filtered Merge

Squash merge a source branch into a new branch off the target, keep only paths matching a filter, then commit, push, and create a PR.

Parameters

Collect via AskUserQuestion (single prompt with all questions):

1. Base branch (required): branch to update (e.g., develop)
2. Source branch (required): branch to take changes from (e.g., base/fanbassador-post)
3. Filter paths (required): space-separated paths to keep (e.g., doc/)
4. Branch name (optional): if not given, auto-generate from filter + base (e.g., sync-doc-to-develop)

If the skill was invoked with an argument, use it as the branch name and skip asking for it.

Workflow

1. git fetch origin
2. Show filtered diff: git diff origin/<base>...<source> -- <filter-paths> --stat
   - If no changes, abort with message
   - Show to user for confirmation before proceeding
3. git checkout -b <branch-name> origin/<base>
4. git merge --squash <source>
5. git reset HEAD
6. git add <filter-paths>
7. git checkout -- . && git clean -fd
8. git diff --cached --stat  (verify only filtered changes staged)
9. Commit with message: "docs: <source> ブランチの変更を <base> に同期"
   - Adjust prefix (docs/feat/fix) based on content
10. git push -u origin <branch-name>
11. gh pr create --base <base> with project CLAUDE.md conventions
12. Return PR URL

Important

• If the project has CLAUDE.md PR conventions (Japanese titles, headers), follow them
• If no changes match the filter, abort early and inform the user
• Never force push