NodeJS: convert stream to buffer and vice versa

streamutils.js

const Readable = require('stream').Readable;

// stream-to-buffer promise variant
module.exports.streamToBufferPromise = function (stream) {
    return new Promise((resolve, reject) => {
        var bufs = [];
        var buffer = null;
        stream.on('error', (error) => { reject(error); });
        stream.on('data', (data) => { bufs.push(data); });
        stream.on('end', () => {
            buffer = Buffer.concat(bufs);
            resolve(buffer);
        });
    });
};

// stream-to-buffer callback variant
module.exports.streamToBuffer = function (stream, cbSuccess, cbError) {
    var bufs = [];
    var buffer = null;
    stream.on('error', (error) => { cbError(error); });
    stream.on('data', (data) => { bufs.push(data); });
    stream.on('end', () => { 
        buffer = Buffer.concat(bufs); 
        cbSuccess(buffer);
    });
};

module.exports.bufferToStream = function (buffer) {
    var stream = new Readable();
    stream.push(buffer);
    stream.push(null);
    return stream;
};