Delete all files from a Slack workspace with a bot token and the Web API

delete-all-files.js

const slack = require('@slack/web-api');
//@see https://api.slack.com/authentication/token-types#bot
const slackClient = new slack.WebClient('<your-bot-token>');

//start deletin'
deleteAllFiles().then(() => {
    logg('All done');
}, err => {
    console.error(err);
});

function logg(msg) {
    console.log(`${new Date().toJSON()} ${msg}`);
}

async function deleteAllFiles() {
    // @note you can start on a later page by adjusting limit/page here
    let limit = 2;

    for (let page = 1; page < limit; page++) {
        logg(`Deleting slack files, page ${page} of ${limit}`);
        //slack returns a paginated list (100 per page) of files
        //@see: https://api.slack.com/methods/files.list
        const filesResp = await slackClient.files.list({ page });

        // remove each file in series using each file `id` value
        for (let file of filesResp.files) {
            const created = new Date(file.created * 1000).toJSON();
            logg(`Deleting file ${file.name} ${file.id}; Size: ${file.size}; Created: ${created}`);
            //@see: https://api.slack.com/methods/files.delete
            await slackClient.files.delete({
                file: file.id
            });
        }

        // update page limit based on slack's response
        if (filesResp.paging && filesResp.paging.pages !== limit) {
            limit = filesResp.paging.pages;
        }
    }

}