// Browser polyfill for Node.js events module
// Minimal EventEmitter implementation for browser tests
export class EventEmitter {
private events: Map<string | symbol, Array<(...args: any[]) => void>> = new Map();
on(event: string | symbol, listener: (...args: any[]) => void): this {
if (!this.events.has(event)) {
this.events.set(event, []);
}
this.events.get(event)!.push(listener);
return this;
}
once(event: string | symbol, listener: (...args: any[]) => void): this {
const onceWrapper = (...args: any[]) => {
this.off(event, onceWrapper);
listener(...args);
};
return this.on(event, onceWrapper);
}
off(event: string | symbol, listener: (...args: any[]) => void): this {
const listeners = this.events.get(event);
if (listeners) {
const index = listeners.indexOf(listener);
if (index !== -1) {
listeners.splice(index, 1);
}
if (listeners.length === 0) {
this.events.delete(event);
}
}
return this;
}
emit(event: string | symbol, ...args: any[]): boolean {
const listeners = this.events.get(event);
if (listeners && listeners.length > 0) {
listeners.forEach((listener) => {
try {
listener(...args);
} catch (error) {
console.error("Error in event listener:", error);
}
});
return true;
}
return false;
}
removeAllListeners(event?: string | symbol): this {
if (event) {
this.events.delete(event);
} else {
this.events.clear();
}
return this;
}
listenerCount(event: string | symbol): number {
return this.events.get(event)?.length || 0;
}
listeners(event: string | symbol): Array<(...args: any[]) => void> {
return this.events.get(event)?.slice() || [];
}
}
export default EventEmitter;
