galaxy_potato_cleaner.js

const fetch = require('node-fetch');

const API_URL = 'https://slack.com/api/';
const TOKEN = '?token=' + 'redacted';

const DEFAULT_COUNT = 100; // as per slack's doc

const PAST_THRESHHOLD = new Date();
    PAST_THRESHHOLD.setHours(-120 * 24, 0, 0, 0);

const IGNORED_CHANNELS = [
    'deathwatch',
];

function getFilesPage(page=1) {
    return fetch(
            API_URL + 'files.list' +
            TOKEN +
            '&page=' + page +
            '&ts_to=' + (PAST_THRESHHOLD.getTime() / 1000).toFixed(0)
        )
        .then(x => x.json())
}

function deleteFile(file) {
    console.warn('deleting', file.id, file.name);
    return fetch(
        API_URL + 'files.delete' +
        TOKEN +
        '&file=' + file.id,
        { method: 'POST' }
    )
    .then(x => x.json())
    .then(x => x.ok);
}

async function main() {
    const pageCount = await getFilesPage().then(x => x.paging.pages);
    const files = [];
    for (let i = 1; i < pageCount + 1; i++) {
        const _files = await getFilesPage(i).then(x => x.files);
        files.push.apply(files, _files);
    }

    console.info(files.length, 'files found before', PAST_THRESHHOLD);

    const ignoredChannels = (await getChannels())
        .filter(x => IGNORED_CHANNELS.indexOf(x.name) > -1);

    const filesToBeDeleted = files.filter(file =>
        (!file.pinned_to || !file.pinned_to.length) &&
        !file.channels.some(x => ignoredChannels.indexOf(x) > -1)
    );

    console.info(filesToBeDeleted.length, 'files to be deleted');

    const oks = await Promise.all(filesToBeDeleted.map(deleteFile));

    if (!oks.every(Boolean)) {
        throw new Error('Some files couldn\'t be delete');
    }
    return oks;
}


async function getChannels() {
    const channels = await fetch(API_URL + 'channels.list' + TOKEN)
        .then(x => x.json())
        .then(x => x.channels);
    return channels;
}

main()
    .then(oks => console.info(oks.length, 'files deleted') || process.exit(0))
    .catch(e => console.error(e) || process.exit(1));