codebase-analysis_skill

Overview

This skill systematically analyzes a JavaScript/TypeScript codebase to reveal structure, dependencies, architectural patterns, and code quality signals. It produces a concise, actionable report that helps developers onboard, plan refactors, and make architectural decisions. The output highlights key files, dependency risks, and prioritized recommendations.

How this skill works

The skill scans project root files (package.json, tsconfig, lockfiles) and maps directory layout using fast file-globbing. It parses dependencies and scripts, detects frameworks and libraries, then searches source files for component, API, and state-management patterns. Finally it runs lightweight checks for linting, tests, TypeScript strictness, TODOs, large files, and dependency issues to generate prioritized findings and next steps.

When to use it

• Onboarding into a new or unfamiliar project
• Before major architectural changes or refactors
• When asked to "analyze", "review", or "audit" the codebase
• Prior to assigning work across teams or feature areas
• To identify technical debt and security/external dependency risks

Best practices

• Start with a high-level scan (package.json, lockfile, build configs) before deep dives
• Analyze large projects by feature or directory to stay inside context limits
• Prefer Glob for discovery and Grep for targeted pattern searches to save time
• Report concrete, prioritized remediation steps with quick wins first
• Include exact file paths and example grep matches to make recommendations actionable

Example use cases

• Produce a Project Overview for a new hire showing tech stack and key directories
• Create a pre-refactor checklist listing risky modules, large files, and TODO hotspots
• Run a dependency health check that highlights outdated or vulnerable packages
• Compare project layout to a template to identify missing standard configs and tooling
• Identify where testing and TypeScript strictness are weak to prioritize quality improvements