Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | 143x 143x 429x 246x 1x 1x | /**
* Event Emitter Bus - Adapter Implementation
*
* In-process EventBus implementation using Node.js EventEmitter.
* This is the ADAPTER for the EventBus PORT.
*
* Can be swapped for RabbitMQ, Kafka, WebSocket, etc. later
* without changing consumers.
*/
import { EventEmitter } from 'node:events';
import type { DomainEvent, EventBus } from './types.js';
/**
* EventEmitter-based implementation of the EventBus interface.
*
* Wraps Node.js EventEmitter to provide type-safe event handling
* that conforms to the EventBus port interface.
*/
export class EventEmitterBus implements EventBus {
private emitter: EventEmitter;
constructor() {
this.emitter = new EventEmitter();
// Allow more listeners for complex systems
this.emitter.setMaxListeners(100);
}
/**
* Emit an event to all subscribed handlers.
* The event's type property determines which handlers receive it.
*/
emit<T extends DomainEvent>(event: T): void {
this.emitter.emit(event.type, event);
}
/**
* Subscribe to events of a specific type.
*/
on<T extends DomainEvent>(
eventType: T['type'],
handler: (event: T) => void
): void {
this.emitter.on(eventType, handler);
}
/**
* Unsubscribe from events of a specific type.
*/
off<T extends DomainEvent>(
eventType: T['type'],
handler: (event: T) => void
): void {
this.emitter.off(eventType, handler);
}
/**
* Subscribe to a single occurrence of an event type.
* Handler is automatically removed after first invocation.
*/
once<T extends DomainEvent>(
eventType: T['type'],
handler: (event: T) => void
): void {
this.emitter.once(eventType, handler);
}
}
|