57 lines
1.9 KiB
TypeScript
57 lines
1.9 KiB
TypeScript
import EventEmitter from 'events';
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export class SaferEmitter extends EventEmitter {
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emit(type: string, ...args: unknown[]) {
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let doError = type === 'error';
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let events = (this as any)._events;
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if (events !== undefined) doError = doError && events.error === undefined;
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else if (!doError) return false;
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// If there is no 'error' event listener then throw.
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if (doError) {
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let er;
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if (args.length > 0) er = args[0];
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if (er instanceof Error) {
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// Note: The comments on the `throw` lines are intentional, they show
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// up in Node's output if this results in an unhandled exception.
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throw er; // Unhandled 'error' event
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}
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// At least give some kind of context to the user
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let err = new Error('Unhandled error.' + (er ? ' (' + (er as any).message + ')' : ''));
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(err as any).context = er;
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throw err; // Unhandled 'error' event
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}
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let handler = events[type];
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if (handler === undefined) return false;
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if (typeof handler === 'function') {
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try {
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Reflect.apply(handler, this, args);
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} catch (error) {
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events[type] = undefined;
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}
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} else {
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let listeners = [...handler];
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listeners
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.filter((e) => {
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try {
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e.call;
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} catch (error) {
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return false;
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}
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return true;
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})
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.forEach((listener) => {
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try {
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Reflect.apply(listener, this, args);
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} catch (error) {
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console.error(error);
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}
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});
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}
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return true;
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}
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}
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