source: frontend/node_modules/get-stream/buffer-stream.js

'use strict';
const {PassThrough: PassThroughStream} = require('stream');

module.exports = options => {
        options = {...options};

        const {array} = options;
        let {encoding} = options;
        const isBuffer = encoding === 'buffer';
        let objectMode = false;

        if (array) {
                objectMode = !(encoding || isBuffer);
        } else {
                encoding = encoding || 'utf8';
        }

        if (isBuffer) {
                encoding = null;
        }

        const stream = new PassThroughStream({objectMode});

        if (encoding) {
                stream.setEncoding(encoding);
        }

        let length = 0;
        const chunks = [];

        stream.on('data', chunk => {
                chunks.push(chunk);

                if (objectMode) {
                        length = chunks.length;
                } else {
                        length += chunk.length;
                }
        });

        stream.getBufferedValue = () => {
                if (array) {
                        return chunks;
                }

                return isBuffer ? Buffer.concat(chunks, length) : chunks.join('');
        };

        stream.getBufferedLength = () => length;

        return stream;
};