Code Quiz

Feature Module Dependency Inversion Leak

A React Native feature module quietly couples its domain logic to a concrete infrastructure class, breaking the architectural boundary.

Codetypescript

// features/cart/domain/CartService.ts
import { StripePaymentApi } from '../../payment/infrastructure/StripePaymentApi';

export interface PaymentGateway {
  charge(amount: number): Promise<void>;
}

export class CartService {
  private readonly payment: PaymentGateway;

  // Domain service accepts an abstraction so it can be tested/swapped
  constructor(payment: PaymentGateway = new StripePaymentApi()) {
    this.payment = payment;
  }

  async checkout(total: number): Promise<void> {
    if (total <= 0) throw new Error('Invalid total');
    await this.payment.charge(total);
  }
}

This domain service is meant to depend only on abstractions. What breaks the layered/modular architecture here?

Next →Dependency Inversion Across Feature Modules