title: How to test `functions.https.onCall` firebase cloud functions locally?
body: <p>I can't seem to find the solution for this in the <a href="https://firebase.google.com/docs/functions/callable" rel="noreferrer">Firebase Documentation</a>.</p>
  <p>I want to test my <code>functions.https.onCall</code> functions locally. Is it possible using the shell or somehow connect my client (firebase SDK enabled) to the local server?</p>
  <p>I want to avoid having to deploy every time just to test a change to my <code>onCall</code> functions.</p>
  <hr />
  <h1>My code</h1>
  <p>Function :</p>
  <pre><code>exports.myFunction = functions.https.onCall((data, context) =&gt; {
    // Do something
  });
  </code></pre>
  <p>Client:</p>
  <pre><code>const message = { message: 'Hello.' };
  
  firebase.functions().httpsCallable('myFunction')(message)
    .then(result =&gt; {
      // Do something //
    })
    .catch(error =&gt; {
      // Error handler //
    });
  </code></pre>