title: Append to a csv file in nodejs (using csv-write-stream)
body: <p>I am currently using <a href="https://www.npmjs.com/package/csv-write-stream" rel="noreferrer">csv-write-stream</a> to write something to a csv file:</p>
  
  <pre><code>var fs = require('fs');
  var csvWriter = require('csv-write-stream')
  
  var writer = csvWriter()
  writer.pipe(fs.createWriteStream('out.csv'))
  writer.write({hello: "world", foo: "bar", baz: "taco"})
  writer.end()
  </code></pre>
  
  <p>I like how easy this is. However, this always creates a new file. How could I append something to this file? Could I even use the same library?</p>