name: git-worktree-use description: Create isolated git worktrees with safety verification. Use when starting feature work needing isolation or before executing plans - systematic directory selection and baseline verification.

Using Git Worktrees

Git worktrees create isolated workspaces sharing the same repository.

Core principle: Systematic directory selection + safety verification = reliable isolation.

When to Use

Use for:

• Feature work needing isolation from current workspace
• Parallel work on multiple branches
• Before executing implementation plans

Don't use for:

• Quick fixes on current branch
• Single-file changes
• When isolation isn't needed

Directory Selection Process

Follow this priority order:

1. 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.

2. Check Project Config

Look for worktree directory preference in project documentation (CLAUDE.md, README, etc.).

If preference specified: Use it without asking.

3. Ask User

If no directory exists and no preference found:

No worktree directory found. Where should I create worktrees?

1. .worktrees/ (project-local, hidden)
2. ~/worktrees/<project-name>/ (global location)

Which would you prefer?

Safety Verification

For Project-Local Directories

MUST verify .gitignore before creating worktree:

grep -q "^\.worktrees/$" .gitignore || grep -q "^worktrees/$" .gitignore

If NOT in .gitignore:

1. Add appropriate line to .gitignore
2. Commit the change
3. Proceed with worktree creation

Why critical: Prevents accidentally committing worktree contents.

For Global Directory

No .gitignore verification needed - outside project entirely.

Creation Steps

1. Detect Project Name

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

2. Create Worktree

git worktree add "$path" -b "$BRANCH_NAME"
cd "$path"

3. Run Project Setup

Auto-detect and run appropriate setup:

# Detect project type and install dependencies
if [ -f package.json ]; then npm install; fi
if [ -f Cargo.toml ]; then cargo build; fi
if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
if [ -f pyproject.toml ]; then pip install -e .; fi
if [ -f go.mod ]; then go mod download; fi

4. Verify Clean Baseline

Run tests to ensure worktree starts clean:

# Use project-appropriate command
npm test / cargo test / pytest / go test ./...

If tests fail: Report failures, ask whether to proceed or investigate.

If tests pass: Report ready.

5. Report Location

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

Quick Reference

Red Flags

Never:

• Create worktree without .gitignore verification (project-local)
• Skip baseline test verification
• Proceed with failing tests without asking
• Assume directory location when ambiguous

Always:

• Follow directory priority: existing > config > ask
• Verify .gitignore for project-local
• Auto-detect and run project setup
• Verify clean test baseline

Integration

Use with:

• brainstorm - After design approval, set up workspace
• task-dispatch - Work happens in this worktree
• completion-verify - Verify baseline before and after