Priority: P0 (CRITICAL)
Core Principles
- SOLID: Follow SRP (One reason to change), OCP (Open to extension), LSP, ISP, DIP.
- KISS/DRY/YAGNI: Favor readability. Abstract repeated logic. No " in case" code.
- Naming: Use intention-revealing names (
isUserAuthenticated>checkUser). Match language casing.
Code Hygiene
- Size Limits: Functions < 30 lines. Services < 600 lines. Utils < 400 lines.
- Early Returns: Use guard clauses. Avoid deep nesting.
- Comments: Explain why, not what. Refactor bad code; don't comment it.
- Input: Validate/sanitize all external inputs.
Anti-Patterns
- No Hardcoded Constants: Use named config/env vars.
- No Deep Nesting: Use guard clauses.
- No Global State: Prefer dependency injection.
- No Empty Catches: Always handle, log, or rethrow.
References
- Code Structure Patterns — file/function organization
- Effectiveness Guide — practical application examples