clean-code
Applies principles from Robert C. Martin's 'Clean Code'. Use this skill when writing, reviewing, or refactoring code to ensure high quality, readability, and maintainability. Covers naming, functions, comments, error handling, and class design.
What this skill does
# Clean Code Skill This skill embodies the principles of "Clean Code" by Robert C. Martin (Uncle Bob). Use it to transform "code that works" into "code that is clean." ## 🧠 Core Philosophy > "Code is clean if it can be read, and enhanced by a developer other than its original author." — Grady Booch ## 1. Meaningful Names - **Use Intention-Revealing Names**: `elapsedTimeInDays` instead of `d`. - **Avoid Disinformation**: Don't use `accountList` if it's actually a `Map`. - **Make Meaningful Distinctions**: Avoid `ProductData` vs `ProductInfo`. - **Use Pronounceable/Searchable Names**: Avoid `genymdhms`. - **Class Names**: Use nouns (`Customer`, `WikiPage`). Avoid `Manager`, `Data`. - **Method Names**: Use verbs (`postPayment`, `deletePage`). ## 2. Functions - **Small!**: Functions should be shorter than you think. - **Do One Thing**: A function should do only one thing, and do it well. - **One Level of Abstraction**: Don't mix high-level business logic with low-level details (like regex). - **Descriptive Names**: `isPasswordValid` is better than `check`. - **Arguments**: 0 is ideal, 1-2 is okay, 3+ requires a very strong justification. - **No Side Effects**: Functions shouldn't secretly change global state. ## 3. Comments - **Don't Comment Bad Code—Rewrite It**: Most comments are a sign of failure to express ourselves in code. - **Explain Yourself in Code**: ```python # Check if employee is eligible for full benefits if employee.flags & HOURLY and employee.age > 65: ``` vs ```python if employee.isEligibleForFullBenefits(): ``` - **Good Comments**: Legal, Informative (regex intent), Clarification (external libraries), TODOs. - **Bad Comments**: Mumbling, Redundant, Misleading, Mandated, Noise, Position Markers. ## 4. Formatting - **The Newspaper Metaphor**: High-level concepts at the top, details at the bottom. - **Vertical Density**: Related lines should be close to each other. - **Distance**: Variables should be declared near their usage. - **Indentation**: Essential for structural readability. ## 5. Objects and Data Structures - **Data Abstraction**: Hide the implementation behind interfaces. - **The Law of Demeter**: A module should not know about the innards of the objects it manipulates. Avoid `a.getB().getC().doSomething()`. - **Data Transfer Objects (DTO)**: Classes with public variables and no functions. ## 6. Error Handling - **Use Exceptions instead of Return Codes**: Keeps logic clean. - **Write Try-Catch-Finally First**: Defines the scope of the operation. - **Don't Return Null**: It forces the caller to check for null every time. - **Don't Pass Null**: Leads to `NullPointerException`. ## 7. Unit Tests - **The Three Laws of TDD**: 1. Don't write production code until you have a failing unit test. 2. Don't write more of a unit test than is sufficient to fail. 3. Don't write more production code than is sufficient to pass the failing test. - **F.I.R.S.T. Principles**: Fast, Independent, Repeatable, Self-Validating, Timely. ## 8. Classes - **Small!**: Classes should have a single responsibility (SRP). - **The Stepdown Rule**: We want the code to read like a top-down narrative. ## 9. Smells and Heuristics - **Rigidity**: Hard to change. - **Fragility**: Breaks in many places. - **Immobility**: Hard to reuse. - **Viscosity**: Hard to do the right thing. - **Needless Complexity/Repetition**. ## 🛠️ Implementation Checklist - [ ] Is this function smaller than 20 lines? - [ ] Does this function do exactly one thing? - [ ] Are all names searchable and intention-revealing? - [ ] Have I avoided comments by making the code clearer? - [ ] Am I passing too many arguments? - [ ] Is there a failing test for this change?
Related in Design
contribute
IncludedLocal-only OSS contribution command center. Auto-refreshes the user's in-flight PR and issue state on invoke so conversations start with full context — no need to brief Claude on what's in flight. Helps the user find issues to contribute to on GitHub, builds per-repo dossiers of what each upstream expects (CLA, DCO, branch convention, AI policy, draft-first, review bots, issue templates), runs deterministic gates before any external action so AI-assisted contributions don't reach maintainers as slop. State is markdown-only: candidate files at ~/.contribute-system/candidates/, repo dossiers at ~/.contribute-system/research/, append-only event log at ~/.contribute-system/log.jsonl. No database, no cloud calls. Use when the user asks about their PRs / issues / contributions, wants to find new work to take on, claim an issue, build/refresh a repo's dossier, or draft a Design Issue or PR. Trigger with "/contribute", "what's my PR status", "find a contribution", "claim issue X", "draft a Design Issue for Y", "refresh dossier for Z".
architectural-analysis
IncludedUser-triggered deep architectural analysis of a codebase or scoped subtree across eight modes — information architecture, data flow, integration points, UI surfaces, interaction patterns, data model, control flow, and failure modes. This skill should be used when the user asks to "diagram this codebase," "map the architecture," "show the data flow," "give me an ERD," "trace control flow," "find the integration points," "verify the layout pattern," "audit the UX architecture," or any similar request whose primary deliverable is mermaid diagrams plus cited reports under docs/architecture/. Dispatches haiku/sonnet sub-agents in parallel for per-mode exploration, then verifies every citation mechanically before any node lands in a diagram. Not for one-off prose explanations of code (use code-explanation) or for high-level system design from scratch (use system-design).
mcp
IncludedModel Context Protocol (MCP) server development and tool management. Languages: Python, TypeScript. Capabilities: build MCP servers, integrate external APIs, discover/execute MCP tools, manage multi-server configs, design agent-centric tools. Actions: create, build, integrate, discover, execute, configure MCP servers/tools. Keywords: MCP, Model Context Protocol, MCP server, MCP tool, stdio transport, SSE transport, tool discovery, resource provider, prompt template, external API integration, Gemini CLI MCP, Claude MCP, agent tools, tool execution, server config. Use when: building MCP servers, integrating external APIs as MCP tools, discovering available MCP tools, executing MCP capabilities, configuring multi-server setups, designing tools for AI agents.
react-native-skia
IncludedDesign, build, debug, and optimise high-polish animated graphics in React Native or Expo using @shopify/react-native-skia, Reanimated, and Gesture Handler. Use when the user wants canvas-driven UI, shaders, paths, rich text, image filters, sprite fields, Skottie, video frames, snapshots, web CanvasKit setup, or performance tuning for custom motion-heavy elements such as loaders, hero art, cards, charts, progress indicators, particle systems, or gesture-driven surfaces. Also use when the user asks for fluid, glow, glass, blob, parallax, 60fps/120fps, or GPU-friendly animated effects in React Native, even if they do not explicitly say "Skia". Do not use for ordinary form/layout work with standard views.
plaid
IncludedProduct Led AI Development — guides founders from idea to launched product. Six capabilities: Idea (discover a product idea), Validate (pressure-test the idea against fatal flaws, problem reality, competition, and 2-week MVP feasibility), Plan (vision intake + document generation), Design (translate image references into a design.md spec), Launch (go-to-market strategy), and Build (roadmap execution). Use when someone says "PLAID", "plaid idea", "help me find an idea", "product idea", "idea from my business", "idea from my expertise", "plaid validate", "validate my idea", "pressure-test", "is this idea good", "find fatal flaws", "validate the problem", "plan a product", "define my vision", "generate a PRD", "product strategy", "plaid design", "design from image", "translate image to design", "create design.md", "extract design tokens", "plaid launch", "go-to-market", "launch plan", "GTM strategy", "launch playbook", "plaid build", "build the app", "start building", or "execute the roadmap".
nextjs-framer-motion-animations
IncludedAdds production-safe Motion for React or Framer Motion animations to Next.js apps, including reveal, hover and tap micro-interactions, whileInView, stagger, AnimatePresence, layout and layoutId transitions, reorder, scroll-linked UI, and lightweight route-content transitions. Use when the user asks to add, refactor, or debug Motion or Framer Motion in App Router or Pages Router codebases, especially around server/client boundaries, reduced motion, LazyMotion, bundle size, hydration, or route transitions. Avoid for GSAP-style timelines, WebGL or 3D scenes, heavy scroll storytelling, or CSS-only effects unless Motion is explicitly requested.