KeyDespesasAngular

Imported from natanaelmarcondes/keydespesas (KeyDespesasAngular/AGENTS.md). Install upstream with npx skills add natanaelmarcondes/keydespesas --skill KeyDespesasAngular. Copyright stays with the author.

You are an expert in TypeScript, Angular, and scalable web application development. You write functional, maintainable, performant, and accessible code following Angular and TypeScript best practices.

TypeScript Best Practices

• Use strict type checking
• Prefer type inference when the type is obvious
• Avoid the any type; use unknown when type is uncertain

Angular Best Practices

• Always use standalone components over NgModules
• Must NOT set standalone: true inside Angular decorators. It's the default in Angular v20+.
• Do NOT set changeDetection: ChangeDetectionStrategy.OnPush explicitly. OnPush is the default in Angular v22+.
• Use signals for state management
• Implement lazy loading for feature routes
• Do NOT use the @HostBinding and @HostListener decorators. Put host bindings inside the host object of the @Component or @Directive decorator instead
• Use NgOptimizedImage for all static images.
  • NgOptimizedImage does not work for inline base64 images.

Accessibility Requirements

• It MUST pass all AXE checks.
• It MUST follow all WCAG AA minimums, including focus management, color contrast, and ARIA attributes.

Components

• Keep components small and focused on a single responsibility
• Use input() and output() functions instead of decorators
• Use model() for two-way bound properties with [(prop)] syntax instead of pairing input() with output()
• Use computed() for derived state
• Use linkedSignal() for state derived from multiple reactive sources that must stay synchronized
• Prefer inline templates for small components
• Prefer Signal Forms (@angular/forms/signals) for new forms. They are stable in Angular v22+ and provide signal-based state, type-safe field access, and schema-based validation
• When not using Signal Forms, prefer Reactive forms instead of Template-driven ones
• Do NOT use ngClass, use class bindings instead
• Do NOT use ngStyle, use style bindings instead
• When using external templates/styles, use paths relative to the component TS file.

State Management

• Use signals for local component state
• Use computed() for derived state
• Keep state transformations pure and predictable
• Do NOT use mutate on signals, use update or set instead

Templates

• Keep templates simple and avoid complex logic
• Use native control flow (@if, @for, @switch) instead of *ngIf, *ngFor, *ngSwitch
• Use the async pipe to handle observables
• Do not assume globals like (new Date()) are available.

Services

• Design services around a single responsibility
• Use the providedIn: 'root' option for singleton services
• Prefer the @Service decorator over @Injectable({providedIn: 'root'}) for new singleton services (Angular v22+)
• Use the inject() function instead of constructor injection