impact-analyzer_skill

Overview

This skill analyzes what parts of a codebase will be affected by a change and helps assess risk before you modify code. It produces a dependency map, risk level, and a practical migration checklist so you can make changes more safely. Use it to catch hidden dependencies, test gaps, and potential breakages early.

How this skill works

You specify a target (file, component, API, or model) and the skill runs an automated dependency analysis against the codebase. It returns an impact summary that lists affected backend, frontend, and test files, assigns a red/yellow/green risk level, and highlights breaking-change risks. Finally, it generates a migration checklist with recommended steps and test coverage gaps to address.

When to use it

• Before modifying a file, service, API endpoint, or data model
• When asked "what will break if I change X" or "is it safe to modify X"
• To discover all callers and consumers of a component or module
• When planning a refactor, upgrade, or API contract change
• To validate deployment risk and testing requirements

Best practices

• Provide an exact target: file path, component name, or API route for precise results
• Run the analyzer early in planning, not just before commit
• Combine findings with test runs and static analysis for full coverage
• Prioritize fixes in areas flagged red and add tests for yellow areas
• Use the migration checklist as a living plan and mark steps as complete

Example use cases

• Ask "What depends on src/services/auth.ts?" to list all callers and impacted services
• Check "Impact of changing the User model" to see DB migrations and API consumers
• Run analysis for an API route like "/api/users/{id}" before altering response shape
• Validate safety of removing or renaming a public function used across repos
• Assess test coverage gaps after a planned refactor to determine required tests