How to check a users permissions in a certain server - discord.js

Question

So I am making a DM command and I want to make it so when the user uses the command it will check the users permissions in a certain server. This is my current code:
bot.on("message", async msg => {
if(msg.channel.type === "dm") {
if(msg.content.startsWith(";announce")) {
if(msg.author.guilds.cache.has("396085313618837526").hasPermission("BAN_MEMBERS")) {
if(!msg.content.split(" ").slice(1).join(" ")) {
msg.reply("I cannot send an announcement without `args`. Please type the command like this: `;announce [MESSAGE]`.")
} else {
let Question1 = new Discord.MessageEmbed()
.setDescription("What channel do you want me to send this in? Please give me the Channel ID (# coming soon).")
msg3 = await msg.channel.send(Question1)
const filter = (m) => m.author.id === msg.author.id
msg.channel.awaitMessages(filter, { max: 1, time: 30000 })
.then(async collected => {
const msg2 = collected.first()
if (!msg2.content) {
msg.reply("You need to give me args. Please retry the command.")
msg2.delete()
} else {
let SendAnnouncement = new Discord.MessageEmbed()
.setTitle("New announcement!")
.setDescription(msg.content.split(" ").slice(1).join(" "))
.setFooter("This announcement has flown in from: " + msg.author.tag)
bot.channels.cache.get(msg2.content).send(SendAnnouncement)
let SuccessfullySent = new Discord.MessageEmbed()
.setDescription("Successfully sent the announcement to <#" + msg2.content + ">!")
msg3.edit(SuccessfullySent)
msg2.delete()
}
})
}
} else {
let error = new Discord.MessageEmbed()
.setDescription("You must have a certain permission to do this. If your roles have just been changed, please type `retry` now so I can check again.")
ERRMSG = await msg.channel.send(error)
const filter = (m) => m.author.id === msg.author.id
msg.channel.awaitMessages(filter, { max: 1, time: 30000 })
.then(async collected => {
const msg2 = collected.first()
if(msg2.content === "retry") {
if(msg.member.hasPermission("BAN_MEMBERS")) {
if(!msg.content.split(" ").slice(1).join(" ")) {
msg.reply("I cannot send an announcement without `args`. Please type the command like this: `;announce [MESSAGE]`.")
} else {
let Question1 = new Discord.MessageEmbed()
.setDescription("What channel do you want me to send this in? Please give me the Channel ID (# coming soon).")
msg3 = await ERRMSG.edit(Question1)
msg2.delete()
const filter = (m) => m.author.id === msg.author.id
msg.channel.awaitMessages(filter, { max: 1, time: 30000 })
.then(async collected => {
const msg2 = collected.first()
if (!msg2.content) {
msg.reply("You need to give me args. Please retry the command.")
msg2.delete()
} else {
let SendAnnouncement = new Discord.MessageEmbed()
.setTitle("New announcement!")
.setDescription(msg.content.split(" ").slice(1).join(" "))
.setFooter("This announcement has flown in from: " + msg.author.tag)
bot.channels.cache.get(msg2.content).send(SendAnnouncement)
let SuccessfullySent = new Discord.MessageEmbed()
.setDescription("Successfully sent the announcement to <#" + msg2.content + ">!")
msg3.edit(SuccessfullySent)
msg2.delete()
}
})
}
} else {
let error2 = new Discord.MessageEmbed()
.setDescription("I still could not find your permissions. Please retry when you have the correct permissions.")
ERRMSG.edit(error2)
msg2.delete()
}
}
})
}
}
}
})
This gives me the error:
(node:347) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'cache' of undefined
(node:347) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:347) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
This just throws this error but I am not sure how I can check the actual permissions in this discord server. How can I manipulate this feature into my Discord Bot?

Answer 1

Well, first of all, you would want to get the guild object of the guild you're referring to, and obviously check if that guild even exists. something that could be done using:
const guildObject = client.guilds.cache.get('place guild id here'); // gets the guild object of the id provided
if (!guildObject) return console.log('Guild could not be found!'); // Would console log in the case that the guild you've provided does not exist.
From there on, we could use the guild object we've found to check if the message author actually exists in this guild, which can be done using
const memberObject = guildObject.member(message.author.id)
if (!memberObject) return console.log('User could not be found in the provided guild!');
Finally, we could determine whether or not the user has the wanted permissions using:
if (!memberObject.hasPermission('Permission here')) return console.log('User does not have the corresponding permissions needed!')

Answer 2

The error you get comes from this line:
if(msg.author.guilds.cache.has("396085313618837526").hasPermission("BAN_MEMBERS"))
What are you checking with this line of code? If the author has permission?
You can check if the author has permission by doing:
if(msg.guild.member(msg.author).hasPermission("BAN_MEMBERS"))