coding-principles_skill

Overview

This skill provides language-agnostic coding principles focused on maintainability, readability, and quality. It distills practical rules for design, error handling, dependency management, performance, testing, security, and documentation. Use it as a lightweight guide when writing, refactoring, or reviewing code to keep systems clean and robust.

How this skill works

The skill inspects common development activities and offers concise, actionable heuristics: prefer simple solutions, enforce single-responsibility functions, group parameters, and separate side effects from transformation logic. It recommends concrete practices for error handling, dependency injection, testing, performance profiling, and secure defaults. It also provides triggers and safe refactoring steps to guide incremental improvements without breaking behavior.

When to use it

• Implementing new features and choosing a design approach
• Refactoring code or reducing technical debt
• Conducting code reviews and preparing PRs
• Designing interfaces, modules, or public APIs
• Writing tests or improving testability

Best practices

• Favor maintainability over short-term speed; delete unused code instead of commenting it out
• Keep functions small (typically <50 lines) and with 0–2 parameters; group related parameters into objects
• Handle errors explicitly, log contextual information, and avoid leaking sensitive data
• Inject dependencies to reduce coupling and make units easier to test
• Profile before optimizing and prefer algorithmic improvements over micro-optimizations

Example use cases

• Refactor a large function into small pure functions and explicit side-effect handlers
• Design an API: apply clear naming, document 'why', and include usage examples
• Prepare a pull request: self-review, keep commits atomic, and remove debug code
• Add robust error propagation and masked logging for production services
• Improve testability by converting hidden dependencies into injectable parameters