Compose:merge

Finishing a Development Branch

Overview

Guide completion of development work by presenting clear options and handling chosen workflow.

Core principle: Verify tests → Detect environment → Present options → Execute choice → Clean up.

Announce at start: "I'm using the compose:merge skill to complete this work."

The Process

Step 1: Verify Tests

Before presenting options, verify tests pass:

# Run project's test suite
npm test / cargo test / pytest / go test ./...

If tests fail:

Tests failing (<N> failures). Must fix before completing:

[Show failures]

Cannot proceed with merge/PR until tests pass.

Stop. Don't proceed to Step 2.

If tests pass: Continue to Step 2.

Step 2: Detect Environment

Determine workspace state before presenting options:

GIT_DIR=$(cd "$(git rev-parse --git-dir)" 2>/dev/null && pwd -P)
GIT_COMMON=$(cd "$(git rev-parse --git-common-dir)" 2>/dev/null && pwd -P)

This determines which menu to show and how cleanup works:

Step 3: Determine Base Branch

# Try common base branches
git merge-base HEAD main 2>/dev/null || git merge-base HEAD master 2>/dev/null

If the base branch is ambiguous, confirm through compose:ask:

• header: Base Branch
• question: This branch appears to have split from <detected>. Correct?
• options:
  • label: Yes, <detected>, description: Use <detected> as merge target
  • label: Different branch, description: I'll specify the correct base branch

If no user is available, use the detected base branch and proceed.

Step 4: Present Options

Normal repo / named-branch worktree — use compose:ask:

• header: Complete Work
• question: Implementation complete. What would you like to do?
• options:
  • label: Merge locally, description: Merge back to <base-branch>
  • label: Create PR, description: Push branch and open a Pull Request
  • label: Keep as-is, description: Leave the branch — I'll handle it later
  • label: Discard, description: Delete branch and all commits

If no user is available, merge locally and proceed.

Detached HEAD — use compose:ask:

• header: Complete Work
• question: Implementation complete (detached HEAD, externally managed). What would you like to do?
• options:
  • label: Create PR, description: Push as new branch and open a PR
  • label: Keep as-is, description: Leave as-is — I'll handle it later
  • label: Discard, description: Delete this work permanently

If no user is available, create a PR and proceed.

Step 5: Execute Choice

Option 1: Merge Locally

# Get main repo root for CWD safety
MAIN_ROOT=$(git -C "$(git rev-parse --git-common-dir)/.." rev-parse --show-toplevel)
cd "$MAIN_ROOT"

# Merge first — verify success before removing anything
git checkout <base-branch>
git pull
git merge <feature-branch>

# Verify tests on merged result
<test command>

# Only after merge succeeds: cleanup worktree (Step 6), then delete branch

Then: Cleanup worktree (Step 6), then delete branch:

git branch -d <feature-branch>

Option 2: Push and Create PR

# Push branch
git push -u origin <feature-branch>

# Create PR
gh pr create --title "<title>" --body "$(cat <<'EOF'
## Summary
<2-3 bullets of what changed>

## Test Plan
- [ ] <verification steps>
EOF
)"

Do NOT clean up worktree — user needs it alive to iterate on PR feedback.

Option 3: Keep As-Is

Report: "Keeping branch . Worktree preserved at ."

Don't cleanup worktree.

Option 4: Discard

Confirm through compose:ask:

• header: Confirm Discard
• question: This will permanently delete branch <name>, all commits, and worktree at <path>. Are you sure?
• options:
  • label: Cancel, description: Keep branch and worktree intact
  • label: Discard permanently, description: Cannot be undone

If no user is available, do NOT discard — keep the branch as-is. (Destructive actions never auto-approve; see compose:ask.)

Only proceed if user selected "Discard permanently". If "Cancel", return to Step 4.

If confirmed:

MAIN_ROOT=$(git -C "$(git rev-parse --git-common-dir)/.." rev-parse --show-toplevel)
cd "$MAIN_ROOT"

Then: Cleanup worktree (Step 6), then force-delete branch:

git branch -D <feature-branch>

Step 6: Cleanup Workspace

Only runs for Options 1 and 4. Options 2 and 3 always preserve the worktree.

GIT_DIR=$(cd "$(git rev-parse --git-dir)" 2>/dev/null && pwd -P)
GIT_COMMON=$(cd "$(git rev-parse --git-common-dir)" 2>/dev/null && pwd -P)
WORKTREE_PATH=$(git rev-parse --show-toplevel)

If GIT_DIR == GIT_COMMON: Normal repo, no worktree to clean up. Done.

If worktree path is under .worktrees/, worktrees/, or ~/.config/compose/worktrees/: Compose created this worktree — we own cleanup.

MAIN_ROOT=$(git -C "$(git rev-parse --git-common-dir)/.." rev-parse --show-toplevel)
cd "$MAIN_ROOT"
git worktree remove "$WORKTREE_PATH"
git worktree prune  # Self-healing: clean up any stale registrations

Otherwise: The host environment (harness) owns this workspace. Do NOT remove it. If your platform provides a workspace-exit tool, use it. Otherwise, leave the workspace in place.

Quick Reference

Common Mistakes

Skipping test verification

• Problem: Merge broken code, create failing PR
• Fix: Always verify tests before offering options

Open-ended questions

• Problem: "What should I do next?" is ambiguous
• Fix: Present exactly 4 structured options (or 3 for detached HEAD)

Cleaning up worktree for Option 2

• Problem: Remove worktree user needs for PR iteration
• Fix: Only cleanup for Options 1 and 4

Deleting branch before removing worktree

• Problem: git branch -d fails because worktree still references the branch
• Fix: Merge first, remove worktree, then delete branch

Running git worktree remove from inside the worktree

• Problem: Command fails silently when CWD is inside the worktree being removed
• Fix: Always cd to main repo root before git worktree remove

Cleaning up harness-owned worktrees

• Problem: Removing a worktree the harness created causes phantom state
• Fix: Only clean up worktrees under .worktrees/, worktrees/, or ~/.config/compose/worktrees/

No confirmation for discard

• Problem: Accidentally delete work
• Fix: Require typed "discard" confirmation

Red Flags

Never:

• Proceed with failing tests
• Merge without verifying tests on result
• Delete work without confirmation
• Force-push without explicit request
• Remove a worktree before confirming merge success
• Clean up worktrees you didn't create (provenance check)
• Run git worktree remove from inside the worktree

Always:

• Verify tests before offering options
• Detect environment before presenting menu
• Present exactly 4 options (or 3 for detached HEAD)
• Get typed confirmation for Option 4
• Clean up worktree for Options 1 & 4 only
• cd to main repo root before worktree removal
• Run git worktree prune after removal