name: git-worktrees description: Create isolated git worktrees for feature work with smart directory selection and safety verification. Use when starting feature work that needs isolation from current workspace or before executing implementation plans.

Git Worktrees

1. Overview

Git worktrees create isolated workspaces sharing the same repository, allowing work on multiple branches simultaneously without switching.

Rule: Systematic directory selection + safety verification = reliable isolation.

2. Directory Selection

Follow this priority order:

Check Existing Directories

ls -d .worktrees 2>/dev/null     # Preferred (hidden)
ls -d worktrees 2>/dev/null      # Alternative

If found, use that directory. If both exist, .worktrees wins.

Check CLAUDE.md

grep -i "worktree.*director" CLAUDE.md 2>/dev/null

If preference specified, use it without asking.

Ask User

If no directory exists and no CLAUDE.md preference:

No worktree directory found. Where should I create worktrees?

1. .worktrees/ (project-local, hidden)
2. A custom global location

Which would you prefer?

3. Safety Verification

For Project-Local Directories (.worktrees or worktrees)

Rule: Verify directory is ignored before creating worktree.

git check-ignore -q .worktrees 2>/dev/null || git check-ignore -q worktrees 2>/dev/null

If NOT ignored: add appropriate line to .gitignore, commit the change, then proceed. This prevents accidentally committing worktree contents to the repository.

For Global Directories

No .gitignore verification needed — outside project entirely.

4. Creation Steps

Detect Project Name

project=$(basename "$(git rev-parse --show-toplevel)")

Create Worktree

# Create worktree with new branch
git worktree add "$LOCATION/$BRANCH_NAME" -b "$BRANCH_NAME"
cd "$LOCATION/$BRANCH_NAME"

Run Project Setup

Auto-detect and run appropriate setup:

# Node.js
if [ -f package.json ]; then npm install; fi
# Rust
if [ -f Cargo.toml ]; then cargo build; fi
# Python
if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
if [ -f pyproject.toml ]; then poetry install; fi
# Go
if [ -f go.mod ]; then go mod download; fi

Verify Clean Baseline

Run tests to ensure worktree starts clean:

npm test / cargo test / pytest / go test ./...

If tests fail, report failures and ask whether to proceed or investigate. If tests pass, report ready.

Report Location

Worktree ready at <full-path>
Tests passing (<N> tests, 0 failures)
Ready to implement <feature-name>

5. Quick Reference

6. Common Mistakes

• Skipping ignore verification — Worktree contents get tracked, pollute git status. Always use git check-ignore before creating project-local worktree.
• Assuming directory location — Creates inconsistency, violates project conventions. Follow priority: existing > CLAUDE.md > ask.
• Proceeding with failing tests — Can't distinguish new bugs from pre-existing issues. Report failures, get explicit permission to proceed.
• Hardcoding setup commands — Breaks on projects using different tools. Auto-detect from project files.

7. Red Flags

Never:

• Create worktree without verifying it's ignored (project-local)
• Skip baseline test verification
• Proceed with failing tests without asking
• Assume directory location when ambiguous

Always:

• Follow directory priority: existing > CLAUDE.md > ask
• Verify directory is ignored for project-local
• Auto-detect and run project setup
• Verify clean test baseline