delete-discord-messages.console.js

// Source: https://gist.github.com/emanzitti/a21c915a5a547aab40d4567d948aa3f6
const GUILD_ID = '',
    AUTHOR_ID = '';

clearMessages = function (guild_id, author_id, authToken, deleted = new Set()) {
    const searchURL = `https://discordapp.com/api/v6/guilds/${guild_id}/messages/search?author_id=${author_id}&include_nsfw=true`
    const headers = { Authorization: authToken }
    let clock = 0
    interval = 750
    function delay(duration) {
        return new Promise((resolve, reject) => {
            setTimeout(resolve, duration)
        })
    }
    function loadMessages() {
        return fetch(searchURL, { headers })
    }
    function tryDeleteMessage(message) {
        if (message.author.id == author_id && !deleted.has(message.id)) { // skip already deleted messages
            console.log(`Deleting message ${message.id} from ${message.author.username} (${message.content}...)`)
            return fetch(`https://discordapp.com/api/v6/channels/${message.channel_id}/messages/${message.id}`, { headers, method: 'DELETE' })
        }
    }
    let messagesStore = []

    loadMessages()
        .then(resp => resp.json())
        .then(messages => {
            messages = messages.messages
            if (messages === undefined || messages === null || messages.length == 0) {
                console.log(`Couldn't load messages. Check guild id, author id, and auth token.`)
                return
            }
            messages = messages.filter(m => m) // clean undefined
            messages = [].concat.apply([], messages); // flatten
            messages = messages.filter(m => m) // clean undefined
            if (messages.length === 0) {
                console.log(`Couldn't load messages. Check guild id, author id, and auth token.`)
                return
            }

            messages = messages.filter(m => m.author.id == author_id)
            console.info(`SUCCESS! Found ${messages.length} messages!`)

            beforeId = messages[messages.length-1].id
            messagesStore = messagesStore.concat(messages)
            return Promise.all(messagesStore.map(message => {
                return delay(clock += interval)
                    .then(() => tryDeleteMessage(message))
                    .then(resp => {
                        if (resp) {
                            if (resp.status == 429) {
                                interval += 1000
                                console.log(`Too fast; bumping interval to ${interval}`)
                            } else if (resp.status === 204) {
                                deleted.add(message.id) // mark deleted
                                return resp.text()
                            }
                        }
                    })
            }))
        })
        .then(function() {
            if (messagesStore.length !== 0) {
                clearMessages(guild_id, author_id, authToken, deleted)
            } else {
                console.log(`We have loaded all messages in this chat.`)
            }
        })
}
var authToken = ""
if (authToken.length === 0) {
    var localToken = document.body.appendChild(document.createElement(`iframe`)).contentWindow.localStorage.token
    if (localToken === undefined) {
        console.log(`Getting the auth token from localStorage isn't supported on Chrome or the desktop client. Use Firefox or grab it from a network request's headers.`)
        console.log(`To do that go to the Network tab of your inspector and copy the Authorization header of a request. There are detailed instructions in the tutorial.`)
    } else {
        authToken = JSON.parse(localToken)
    }
}
if (authToken.length !== 0) {
    clearMessages(GUILD_ID, AUTHOR_ID, authToken)
}