javascript - Cannot read properties of undefined when it shouldn't be undefined in discord.js command handler

Question

I created a small command handler with a simple "ping" command. However, trying to access message.channel shows up undefined. Why is this?

./index.js

//Discord, fs, prefix, client etc. declarations

client.commands = new Collection()

const files = fs.readdirSync("./commands").filter(file => file.endsWith(".js")

for (const file of files) {
  const command = require(`./commands/${file}`)
  client.commands.set(command.name, command)
}

client.on("messageCreate", message => {
  const [command, ...args] = message.content.slice(prefix.length).split(/ +/g)
  if (client.commands.has(command) {
    client.commands.get(command).execute(message, client, args)
  }
})

client.login(/*token*/)

./commands/ping.js

module.exports = {
  name: "ping",
  description: "Make me say pong",
  async execute(client, message, args) {
    message.channel.send("Pong!")
  }
}

Answer 1

While Message.channel may be valid, message is not an instance of Message. It is actually an instance of Client. The order of the arguments always matter, and putting them in the wrong order can throw TypeErrors. There is 1 simple solution here

Make the arguments in the right order! You can either change the execution, or the declaration

client.commands.get(command).execute(client, message, args)

This is really common and happens for more than sending messages to channels