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

'use strict';

const isStream = stream =>
        stream !== null &&
        typeof stream === 'object' &&
        typeof stream.pipe === 'function';

isStream.writable = stream =>
        isStream(stream) &&
        stream.writable !== false &&
        typeof stream._write === 'function' &&
        typeof stream._writableState === 'object';

isStream.readable = stream =>
        isStream(stream) &&
        stream.readable !== false &&
        typeof stream._read === 'function' &&
        typeof stream._readableState === 'object';

isStream.duplex = stream =>
        isStream.writable(stream) &&
        isStream.readable(stream);

isStream.transform = stream =>
        isStream.duplex(stream) &&
        typeof stream._transform === 'function';

module.exports = isStream;