discord js get author mention from message code example

Example 1: check if message mentions users discord js

// 1st Way
if (<Message>.mentions.members.size) { // or message.mentions.members.size > 0
  //DO STUFF
}

// 2nd Way
if (<Message>.mentions.members.first()) {
  //DO STUFF
}

Example 2: how to read if a person has send a message on discord.js

client.on('message', message => {
  // this function can check whether the content of the message you pass is the same as this message
  let filter = msg => {
    return msg.content.toLowerCase() == message.content.toLowerCase() && // check if the content is the same (sort of)
           msg.author == message.author; // check if the author is the same
  }

  message.channel.awaitMessages(filter, {
    maxMatches: 1, // you only need that to happen once
    time: 5 * 1000 // time is in milliseconds
  }).then(collected => {
    // this function will be called when a message matches you filter
  }).catch(console.error);
});