Skill Isolation Tester

Tests Claude Code skills in isolated environments to ensure they work correctly without dependencies on your local setup.

When to Use

Trigger Phrases:

• "test skill [name] in isolation"
• "validate skill [name] in clean environment"
• "test my new skill in worktree/docker/vm"
• "check if skill [name] has hidden dependencies"

Use Cases:

• Test before committing or sharing publicly
• Validate no hidden dependencies on local environment
• Verify cleanup behavior (no leftover files/processes)
• Catch environment-specific bugs

Quick Decision Matrix

Risk-Based Auto-Detection

Mode 1: Git Worktree (Fast)

Best for: Low-risk skills, quick iteration

Process:

1. Create isolated git worktree
2. Install Claude Code
3. Copy skill and run tests
4. Cleanup

Workflow: modes/mode1-git-worktree.md

Mode 2: Docker Container (Balanced)

Best for: Medium-risk skills, full OS isolation

Process:

1. Build/pull Docker image
2. Create container with Claude Code
3. Run skill tests with monitoring
4. Cleanup container and images

Workflow: modes/mode2-docker.md

Mode 3: VM (Safest)

Best for: High-risk skills, untrusted code

Process:

1. Provision VM, take snapshot
2. Install Claude Code
3. Run tests with full monitoring
4. Rollback or cleanup

Workflow: modes/mode3-vm.md

Test Templates

Production-ready templates in test-templates/:

Usage:

chmod +x test-templates/docker-skill-test.sh
./test-templates/docker-skill-test.sh my-skill-name

# CI/CD with JSON output
export JSON_ENABLED=true
./test-templates/docker-skill-test-json.sh my-skill-name

Helper Library

lib/docker-helpers.sh provides robust Docker testing utilities:

source ~/.claude/skills/skill-isolation-tester/lib/docker-helpers.sh

trap cleanup_on_exit EXIT
preflight_check_docker || exit 1
safe_docker_build "Dockerfile" "skill-test:my-skill"
safe_docker_run "skill-test:my-skill" bash -c "echo 'Testing...'"

Functions: validate_shell_command, retry_docker_command, cleanup_on_exit, preflight_check_docker, safe_docker_build, safe_docker_run

Validation Checks

Execution:

• Skill completes without errors
• Output matches expected format
• Execution time acceptable

Side Effects:

• No orphaned processes
• Temporary files cleaned up
• No unexpected system modifications

Portability:

• No hardcoded paths
• All dependencies documented
• Works in clean environment

Test Report Format

# Skill Isolation Test Report: [skill-name]
## Environment: [Git Worktree / Docker / VM]
## Status: [PASS / FAIL / WARNING]

### Execution Results
✅ Skill completed successfully

### Side Effects Detected
⚠️ 3 temporary files not cleaned up

### Dependency Analysis
📦 Required: jq, git

### Overall Grade: B (READY with minor fixes)

Reference Materials

• modes/mode1-git-worktree.md - Fast isolation workflow
• modes/mode2-docker.md - Container isolation workflow
• modes/mode3-vm.md - Full VM isolation workflow
• data/risk-assessment.md - Skill risk evaluation
• data/side-effect-checklist.md - Side effect validation
• templates/test-report.md - Report template
• test-templates/README.md - Template documentation

Quick Commands

# Test with auto-detection
test skill my-new-skill in isolation

# Test in specific environment
test skill my-new-skill in worktree  # Fast
test skill my-new-skill in docker    # Balanced
test skill my-new-skill in vm        # Safest

Version: 0.1.0 | Author: Connor