coding

name	coding
description	Code implementation and feature development. Use this skill when implementing features, fixing bugs, or making tests pass. This is the GREEN phase of TDD — write minimal code to pass tests, then refactor. Also use the tdd, refactor, and design skills.

Coding Skill

This skill guides code implementation — the GREEN phase of TDD.

Core Process

1. Understand the tests — Read failing tests to understand required behavior
2. Implement minimally — Write the simplest code that makes tests pass
3. Refactor — Improve structure while keeping tests green (invoke the refactor skill)

Related Skills

• tdd — Writing tests (RED phase) before implementation
• refactor — Improving code structure (REFACTOR phase) after tests pass
• design — Software design principles for architectural decisions
• code-quality — Naming, structure, and maintainability guidelines
• security — Secure coding practices

Principles

Follow Existing Patterns

Before writing new code:

• Read surrounding code to understand conventions
• Match the style, naming, and structure of the existing codebase
• Reuse existing abstractions rather than creating new ones

Simplicity

• Solve the immediate problem, not hypothetical future ones
• Prefer clear, readable code over clever code
• Each method should do one thing at one level of abstraction

Immutability

• Initialize all state in constructors
• Avoid mutating objects after creation
• Exception: memoization/lazy initialization is acceptable

Error Handling

• Validate at system boundaries (user input, external APIs)
• Trust internal code and framework guarantees
• Provide helpful error messages

Workflow Integration

After implementation:

1. Run tests to verify they pass
2. Run linting to check style
3. Invoke the refactor skill for cleanup
4. Request code review via the SDLC process