📏 Rules

Rules are guidelines that the AI must always follow to ensure code quality and team consistency.

What Are Rules?

Rules are like team conventions:

• 🎨 Code style (indentation, naming, formatting)
• 🔒 Security standards (secret management, input validation)
• 🏗️ Architecture conventions (directory structure, layered design)
• 🧪 Testing requirements (coverage, testing strategy)

Rule Hierarchy

1. Global Rules

Apply to all projects, configured in ~/.claude/rules/:

~/.claude/rules/
├── common/
│   ├── coding-style.md
│   ├── security.md
│   └── testing.md
└── typescript/
    ├── coding-style.md
    └── patterns.md

2. Project Rules

Apply to specific projects, configured in the project root .codebuddy/rules/:

your-project/
└── .codebuddy/rules/
    ├── project-conventions.md
    └── api-design.md

Core Rule Examples

Coding Style Rules

# TypeScript Coding Style

## Naming Conventions
- Variables/Functions: camelCase
- Classes/Interfaces: PascalCase
- Constants: UPPER_SNAKE_CASE
- File names: kebab-case.ts

## Prohibited
- ❌ Using the any type
- ❌ console.log in production code
- ❌ Hardcoded secrets or passwords

Security Rules

# Security Rules

## Secret Management
✅ CORRECT:
const apiKey = process.env.API_KEY

❌ WRONG:
const apiKey = "sk-xxxxx"

## Input Validation
- All user input must be validated
- Use Zod for schema validation

Testing Rules

# Testing Rules

## Coverage Requirements
- Core business logic: >= 80%
- Utility functions: >= 90%
- UI components: >= 70%

## Test Naming
describe('ComponentName', () => {
  it('should [expected behavior] when [condition]', () => {})
})

Rule File Format

Rule files use Markdown format with the following structure:

---
name: my-rule
priority: high
scope: typescript
---

File content structure:

• # Rule Name - Rule title
• ## Background - Why this rule is needed
• ## Rule Content - Specific rule descriptions
• ## Correct Examples - Show correct code patterns
• ## Wrong Examples - Show incorrect code patterns
• ## Exceptions - When exceptions are allowed

Rule Priority

Rules are applied in the following priority order:

1. Project Rules - Highest priority
2. Language-Specific Rules - Secondary priority
3. Global Common Rules - Baseline rules

Installing Language Rule Packs

ECC provides pre-configured language rule packs:

# Install TypeScript rules
cp -r rules/typescript/* ~/.codebuddy/rules/

# Install Python rules
cp -r rules/python/* ~/.codebuddy/rules/

# Install Go rules
cp -r rules/golang/* ~/.codebuddy/rules/

Best Practices

1. Be specific - Avoid vague descriptions
2. Provide examples - Show both correct and incorrect code
3. Explain the why - Explain why the rule exists
4. Allow exceptions - Clearly state when exceptions are acceptable
5. Update regularly - Update rules as the project evolves

---

💡 Tip: Good rules should be team consensus — it's recommended to discuss with the team before adding new rules!