ECC/rules/patterns.md

Common Patterns

API Response Format

interface ApiResponse<T> {
  success: boolean
  data?: T
  error?: string
  meta?: {
    total: number
    page: number
    limit: number
  }
}

Custom Hooks Pattern

export function useDebounce<T>(value: T, delay: number): T {
  const [debouncedValue, setDebouncedValue] = useState<T>(value)

  useEffect(() => {
    const handler = setTimeout(() => setDebouncedValue(value), delay)
    return () => clearTimeout(handler)
  }, [value, delay])

  return debouncedValue
}

Repository Pattern

interface Repository<T> {
  findAll(filters?: Filters): Promise<T[]>
  findById(id: string): Promise<T | null>
  create(data: CreateDto): Promise<T>
  update(id: string, data: UpdateDto): Promise<T>
  delete(id: string): Promise<void>
}

Skeleton Projects

When implementing new functionality:

1. Search for battle-tested skeleton projects
2. Use parallel agents to evaluate options:
   • Security assessment
   • Extensibility analysis
   • Relevance scoring
   • Implementation planning
3. Clone best match as foundation
4. Iterate within proven structure