SOLID Rust - Modular Architecture
Agent Workflow (MANDATORY)
Before ANY implementation, use TeamCreate to spawn 3 agents:
- fuse-ai-pilot:explore-codebase - Analyze existing architecture
- fuse-ai-pilot:research-expert - Verify Rust docs via Context7
- fuse-ai-pilot:sniper - Post-implementation validation
DRY - Reuse Before Creating (MANDATORY)
Before writing ANY new code:
- Grep the codebase for similar traits, services, or logic
- Check shared locations:
src/core/services/,src/core/traits/ - If similar code exists -> extend/reuse instead of duplicate
- If code will be used by 2+ features -> create it in
src/core/
Architecture (Modules MANDATORY)
| Layer | Location | Max Lines |
|-------|----------|-----------|
| Handlers | src/modules/[feature]/handlers.rs | 50 |
| Services | src/modules/[feature]/services.rs | 100 |
| Repositories | src/modules/[feature]/repository.rs | 100 |
| Traits | src/modules/[feature]/traits.rs | 30 |
| Models | src/modules/[feature]/models.rs | 50 |
| Shared | src/core/{services,traits,models}/ | - |
NEVER use flat src/ structure - always src/modules/[feature]/
Critical Rules (MANDATORY)
| Rule | Value |
|------|-------|
| File limit | 100 lines (split at 90) |
| Handlers | < 50 lines, delegate to services |
| Traits | traits.rs or src/core/traits/ ONLY |
| Rustdoc | /// on every public item |
| Error handling | Use thiserror for custom errors |
| Generics | Use trait bounds, not concrete types |
Reference Guide
Concepts
| Topic | Reference | When to consult | |-------|-----------|-----------------| | SOLID Overview | solid-principles.md | Quick reference | | SRP | single-responsibility.md | Fat structs | | OCP | open-closed.md | Adding impls | | LSP | liskov-substitution.md | Trait contracts | | ISP | interface-segregation.md | Fat traits | | DIP | dependency-inversion.md | Generics/DI | | Architecture | architecture-patterns.md | Modular crate |
Templates
| Template | When to use | |----------|-------------| | module.md | Feature module structure | | service.md | Business logic service | | trait-def.md | Trait definition | | handler.md | HTTP handler (Axum) | | error.md | Custom errors (thiserror) | | test.md | Unit + integration tests |
Forbidden
| Anti-Pattern | Fix |
|--------------|-----|
| Files > 100 lines | Split at 90 |
| Traits in impl files | Move to traits.rs |
| Box<dyn Any> | Use proper trait bounds |
| Flat src/ structure | Use src/modules/[feature]/ |
| Unwrap in library code | Use Result<T, E> |