nodeJS-ioredis NPM模块-订户事件有问题

Question

const Redis = require('ioredis');

const sub = new Redis();
const pub = new Redis();

sub.on('subscribe', (channel, count) => {
    console.log("Subbed to channel: " + channel);
})

sub.on('message', (channel, message) => {
    console.log("Message recieved: " + message);
})

setTimeout(() => {
    console.log("Attempting");
    sub.subscribe("hey");
    pub.publish("hey", "msg");
}, 2000);

这是我一直在测试的代码，它会产生以下控制台输出：

Attempting

Message recieved: msg

预期输出：

Attempting

Subbed to channel: hey

Message recieved: msg

sub.on（'subscribe'）事件似乎没有触发。