emoji downloader

slack-emoji-export.js

const Slack = require ( 'slack-node' );
const http  = require ( 'https' );
const fs    = require( 'fs' );

const apiToken = "YOUR_SLACK_TEAM_API_TOKEN"; 

// interval for file download (msec)
const wait = 250;

const get = url => new Promise ( ( resolve, reject ) => {
        http.get( url, res => {
            const { statusCode } = res;

            let error;
            
            if ( statusCode !== 200 ) {
                error = new Error('Request Failed.\n' +
                                  `Status Code: ${statusCode}`);
            }
            
            if ( error ) {
                // consume response data to free up memory
                res.resume();
                reject( error.message );
                return;
            }
            
            let data = [ ];

            res.on( 'data', chunk => {
                data.push( chunk );
            } ).on( 'end', ( ) => {
                const binary = Buffer.concat( data );
                setTimeout( resolve, wait, binary );
            } );
            
        } ).on('error', error => {
            reject( `Got error: ${error.message}` );
        } );
} );


const slack = new Slack( apiToken );

slack.api( "emoji.list", async ( error, response ) => {
    if ( error || ! response.emoji ) {
        console.log( `Got error: ${error.message}` );
        return;
    }
    for ( let name in response.emoji ){
        const url = response.emoji[ name ];
        if( url === undefined ||  url.match(/^alias:/) ){
            continue;
        }
        const binary = await get( url );
        const ext = url.match( /\.[^\.]+$/ );
        fs.writeFileSync( `images/${name}${ext}`, binary );
        console.log( `${name} download done.` );
    }
} );