一段时间后运行 function 而不阻塞执行线程

Question

I've been working on a Discord bot using Discord.js and I've run into a frustrating limitation of Javascript that I'm trying to find a workaround for.

Essentially, I come to a point in my code where I want to wait a set period of time.

Currently, I have this implemented in my code as

while (new Date().getTime() < targetTime)
{
    //Waiting
}

The problem is that other aspects of my code can not function while this while loop is in action. For example, I have an event listener for anytime a user sends a message in Discord, but the listener does not work while the while loop is executing.

client.on('message', async message => {
     //stuff happens here
}

Any recommendations on how to get this to work?

Answer 1

That is expected behavior, the main thread is "busy" getting a current date on every thick. So he cannot do anything else, because js is single-threaded.

You can use node-schedule npm package which implements a better algorithm for observing the current date.

const date = new Date(2020, 1, 22, 12, 0, 0);

schedule.scheduleJob(date, function(){
  console.log('job is running');
});