Cursor rule

1---
2description: Clean Architecture patterns and layer separation
3globs: web/src/**/*.ts
4alwaysApply: false
5---
6 
7# Architecture and Separation of Concerns
8 
9## Layers and Dependencies
10 
11Dependencies flow only inward (presentation → application → domain).
12 
13### Domain (src/domain/)
14- Value entities: `Money`, `StockQuantity`, `StockPosition`
15- Operations: `VestingOperation`, `TradeOperation`
16- Domain services: `PortfolioCalculationService`, `PortfolioAnalyticsService`
17- Zero external dependencies. Pure, testable logic.
18 
19### Application (src/application/)
20- Interfaces (contracts): `IOperationRepository`, `IDataExportService`
21- Use cases: `ProcessPortfolioUseCase`
22- Orchestrates the flow without containing business rules.
23 
24### Infrastructure (src/infrastructure/)
25- Concrete implementations of contracts: `PDFOperationRepository`, `JSONOperationRepository`
26- External services: `BCBExchangeRateService`, `CSVExportService`
27- Utilities: `DateParser`
28 
29### Presentation (src/presentation/)
30- UI controllers: `PortfolioApp`
31- HTML builders: `ModalBuilder`, `YearDetailsBuilder`
32- Formatters: `BRLFormatter`, `USDFormatter`
33 
34## Applied Patterns
35 
36- **Repository Pattern**: abstract data sources behind an interface
37- **Composite Pattern**: `CompositeOperationRepository` combines multiple sources
38- **Dependency Injection**: pass dependencies via constructor
39- **Use Case Pattern**: one class per use case
40- **Builder Pattern**: construct complex HTML elements
41 
42## When Creating New Code
43 
441. Ask: "Is this business logic?" → `domain/`
452. Ask: "Does this orchestrate a flow?" → `application/`
463. Ask: "Does this communicate with something external?" → `infrastructure/`
474. Ask: "Does this manipulate the UI?" → `presentation/`
48