title: What is the test command while creating package.json?
body: <p>While creating <code>package.json</code> from command line using <code>npm init</code> for creating a module in Node.js, there is a <strong>test command</strong> field that I don't know about. There's no mention of it in the docs too on executing <code>npm help json</code> also in the CLI.</p>
  
  <p>Please explain what it is about.</p>