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

'use strict';
const {constants: BufferConstants} = require('buffer');
const stream = require('stream');
const {promisify} = require('util');
const bufferStream = require('./buffer-stream');

const streamPipelinePromisified = promisify(stream.pipeline);

class MaxBufferError extends Error {
        constructor() {
                super('maxBuffer exceeded');
                this.name = 'MaxBufferError';
        }
}

async function getStream(inputStream, options) {
        if (!inputStream) {
                throw new Error('Expected a stream');
        }

        options = {
                maxBuffer: Infinity,
                ...options
        };

        const {maxBuffer} = options;
        const stream = bufferStream(options);

        await new Promise((resolve, reject) => {
                const rejectPromise = error => {
                        // Don't retrieve an oversized buffer.
                        if (error && stream.getBufferedLength() <= BufferConstants.MAX_LENGTH) {
                                error.bufferedData = stream.getBufferedValue();
                        }

                        reject(error);
                };

                (async () => {
                        try {
                                await streamPipelinePromisified(inputStream, stream);
                                resolve();
                        } catch (error) {
                                rejectPromise(error);
                        }
                })();

                stream.on('data', () => {
                        if (stream.getBufferedLength() > maxBuffer) {
                                rejectPromise(new MaxBufferError());
                        }
                });
        });

        return stream.getBufferedValue();
}

module.exports = getStream;
module.exports.buffer = (stream, options) => getStream(stream, {...options, encoding: 'buffer'});
module.exports.array = (stream, options) => getStream(stream, {...options, array: true});
module.exports.MaxBufferError = MaxBufferError;