Before writing any new code it requires a DRY check against modules/core/services and modules/core/interfaces. See solid-principles.md for the overview, the per-principle references for SRP/OCP/LSP/ISP/DIP detail, and the templates for module/service/interface/repository/error/test scaffolding.
SOLID Java - Modular Architecture
Agent Workflow (MANDATORY)
Before ANY implementation, spawn 3 agents in parallel, one Agent call each with a name:
- fuse-ai-pilot:explore-codebase - Analyze existing architecture
- fuse-ai-pilot:research-expert - Verify Java 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 interfaces, services, or logic
- Check shared locations:
modules/core/services/, modules/core/interfaces/
- If similar code exists -> extend/reuse instead of duplicate
- If code will be used by 2+ features -> create it in
modules/core/
Architecture (Modules MANDATORY)
| Layer |
Location |
| Controllers |
modules/[feature]/controllers/ |
| Services |
modules/[feature]/services/ |
| Repositories |
modules/[feature]/repositories/ |
| Interfaces |
modules/[feature]/interfaces/ |
| Models/DTOs |
modules/[feature]/models/ |
| Shared |
modules/core/{services,interfaces,models}/ |
NEVER use flat src/ structure - always modules/[feature]/
Critical Rules (MANDATORY)
| Rule |
Value |
| File limit |
FUSE_SOLID_MAX_LINES |
| Controllers |
Thin, delegate to services |
| Interfaces |
modules/[feature]/interfaces/ ONLY |
| Javadoc |
Every public method documented |
| Records |
Use for DTOs (Java 16+) |
| Sealed |
Use for restricted hierarchies (Java 17+) |
Reference Guide
Concepts
Templates
Forbidden
| Anti-Pattern |
Fix |
Files over FUSE_SOLID_MAX_LINES |
Split by responsibility |
| Interfaces in impl files |
Move to interfaces/ directory |
new ConcreteClass() in services |
Use dependency injection |
Flat src/ structure |
Use modules/[feature]/ |
| God classes |
Split by responsibility |
