@tinkoff/pubsub/lib/pubsub/PubSub.es.js

Implementation of the publish/subscribe pattern

import noop from '@tinkoff/utils/function/noop';

const mockLogger = {
    debug: noop,
    info: noop,
    error: noop,
};
const defaultOptions = {
    logger: mockLogger,
    resultTransform: (res) => {
        if (res.length === 1) {
            return res[0];
        }
        return res;
    },
};
class PubSub {
    constructor(options) {
        this.subscribers = new Map();
        const opts = { ...defaultOptions, ...options };
        this.logger = opts.logger;
        this.resultTransform = opts.resultTransform;
    }
    subscribe(event, fn) {
        this.logger.debug('subscribe', event, fn);
        let subs = this.subscribers.get(event);
        if (subs) {
            subs.add(fn);
        }
        else {
            subs = new Set([fn]);
            this.subscribers.set(event, subs);
        }
        return () => subs.delete(fn);
    }
    publish(event, ...args) {
        this.logger.debug('publish', event, args);
        const subs = this.subscribers.get(event);
        if (subs && subs.size) {
            const promises = [];
            subs.forEach((sub) => promises.push(Promise.resolve(sub(...args))));
            return Promise.all(promises).then(this.resultTransform);
        }
        return Promise.resolve();
    }
}

export { PubSub };