code-analysis_skill

Overview

This skill provides practical methodologies, metrics, and best practices for analyzing code structure, complexity, and quality across multiple languages. It helps identify complexity hotspots, common code smells, and actionable refactoring strategies to improve maintainability and testability.

How this skill works

The skill inspects code metrics such as cyclomatic and cognitive complexity, file and function sizes, parameter counts, nesting depth, and duplication patterns. It highlights anti-patterns (long methods, god objects, dead code) and maps each finding to concrete refactor suggestions and priority levels. Reports can be used to guide code reviews, automated gating, and continuous improvement efforts.

When to use it

• During code reviews to prioritize risky changes
• When onboarding to a new codebase to learn structure and hotspots
• Before major refactors or releases to reduce technical debt
• As part of CI pipelines to enforce quality gates
• When tracking longitudinal code quality and team progress

Best practices

• Set concrete thresholds for metrics (e.g., cyclomatic complexity bands) and apply them consistently
• Combine automated detection with human review — tools find candidates, developers validate intent
• Prioritize refactors by impact and risk; fix high-complexity, frequently changed code first
• Prefer small, reversible refactors (extract method/class) and add tests before changes
• Track trends over time and integrate findings into team retrospectives

Example use cases

• Run a baseline analysis to find files with cyclomatic complexity >20 and schedule refactors
• Detect duplicated code blocks across the project and plan extraction to shared utilities
• Identify long parameter lists and apply parameter object or builder refactors
• Locate deep nesting and replace conditionals with guard clauses or polymorphism
• Scan for dead code and remove unused functions after ensuring test coverage