is-stream Check if something is a Node.js stream Install $ npm install --save is-stream Usage var fs = require('fs'); var isStream = require('is-stream'); isStream(fs.createReadStream('unicorn.png')); //=> true isStream({}); //=> false API isStream(stream) isStream.writable(stream) isStream.readable(stream) isStream.duplex(stream) License MIT © Sindre Sorhus