Cannot read the property 'roles' of undefined - discord.js

Question

I'm making a bot and I have an error that I don't understand in this code : pas
const Discord = require("discord.js");
const client = new Discord.Client();
const token = "";
client.login(token)
client.on("message", async(message) => {
let staffRole = message.guild.roles.find("name", "Staff");
let staff = message.guild.member(message.author);
if (message.author.id === "424974772959444993" || message.member.roles.has(staffRole.id)) {
return;
}
var badWords = [
'asd',
'legionmods',
'verga',
'vrga',
'nmms',
'alv',
'electromods',
'remake'
];
var words = message.content.toLowerCase().trim().match(/\w+|\s+|[^\s\w]+/g);
var containsBadWord = words.some(word => {
return badWords.includes(word);
});
if (containsBadWord) {
message.delete();
message.author.send({embed: {
color: 3447003,
description: `Has dicho una palabra que no esta permitida en este servidor`
}
message.channel.send(`${prefix}tempmute ${message.author}`+" 5m palabra prohibida")
}
});
This is an error I get :
(node:4952) UnhandledPromiseRejectionWarning: TypeError: Cannot read property
'roles' of null
at Client.client.on (C:\Users\Francisco\Desktop\role\app.js:8:33)
Could someone help me please ? I am not good in debugging errors.

Answer 1

message.guild is probably returning null because the message was sent in a dm conversation, not a guild.
You can avoid this problem by writing:
if (message.channel.type !== 'text') return;
Also, a few GuildMemberRoleManager methods have changed a bit since discord.js v12+. You should replace:
let staffRole = message.guild.roles.find("name", "Staff");
With:
let staffRole = message.guild.roles.cache.find(role => role.name === "Staff");
And replace:
message.member.roles.has(staffRole.id)
With:
message.member.roles.cache.has(staffRole.id)