dispacher.js

function noop() {
}

class Dispatcher {
	constructor() {
		this.ctx = {
			tasks: [],
			done: noop,
			context: {}
		};
	}

	use(task) {
		this.ctx.tasks.push(task);

		return this;
	}

	done(done) {
		this.ctx.done = done;
		return this;
	}

	run() {
		var ctx = this.ctx;

		return dispatch(0);

		function dispatch(idx) {
			let task = ctx.tasks[idx];

			if (ctx.tasks.length == idx) task = ctx.done;

			function next() {
				idx++;
				dispatch(idx);
			}

			if (!task) {
				return;
			}

			return task(ctx.context, next);
		}
	}
}

module.exports = new Dispatcher();
module.noop = noop;

example.js

const dispatcher = require('./dispacher.js');

dispatcher.use(function (ctx, next) {
    console.log('A');

    setTimeout(function () {
        console.log('1s A');
        next();
    }, 1000);
});

dispatcher.use(function (ctx, next) {
    console.log('B');
    next();
});

dispatcher.done(function () {
    console.log('done');
});

dispatcher.run();