ghostfolio/node_modules/@angular/core/resources/best-practices.md

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+.
• 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 computed() for derived state
• Set changeDetection: ChangeDetectionStrategy.OnPush in @Component decorator
• Prefer inline templates for small components
• 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.
• Do not write arrow functions in templates (they are not supported).

Services

• Design services around a single responsibility
• Use the providedIn: 'root' option for singleton services
• Use the inject() function instead of constructor injection