title: node assert: Test error message
body: <p>Using node's assert module how can I test the message of an error?</p>
  
  <pre><code>throw new Error('Email is required!');
  </code></pre>
  
  <p>I'm using assert.throws to check if an error was thrown:</p>
  
  <pre><code>assert.throws(myFunction, Error);
  </code></pre>
  
  <p>But this does not provide the ability to check the message.</p>