Comprehensive best practices guide for NestJS applications. Contains 40 rules across 10 categories, prioritized by impact to guide automated refactoring and code generation.
Rule Categories by Priority
| Priority | Category | Impact | Prefix |
|---|---|---|---|
| 1 | Architecture | CRITICAL | arch- |
| 2 | Dependency Injection | CRITICAL | di- |
| 3 | Error Handling | HIGH | error- |
| 4 | Security | HIGH | security- |
| 5 | Performance | HIGH | perf- |
| 6 | Testing | MEDIUM-HIGH | test- |
| 7 | Database & ORM | MEDIUM-HIGH | db- |
| 8 | API Design | MEDIUM | api- |
| 9 | Microservices | MEDIUM | micro- |
| 10 | DevOps & Deployment | LOW-MEDIUM | devops- |
How to find a rule
Each rule lives in its own file under rules/, named <prefix>-<rule>.md (e.g.
rules/arch-avoid-circular-deps.md, rules/security-validate-all-input.md); the prefixes map
to the category table above and rules/_sections.md lists every rule per
category. Read only the rules the task touches — each file carries the why, an incorrect and a
correct code example, and extra context.