title: How do I resolve new ESLint errors in my Cloud Functions project?
body: <p>Another day another question regarding Firebase:</p>
  
  <p>I am relatively new to Firebase/node.js/npm ...</p>
  
  <p>I'm currently trying to build a mobile app backend with Firebase for a university project. I use node.js and <strong>write, not test</strong> my functions locally, then I deploy them using the Firebase CLI and "firebase deploy".
  Everything worked out fine until I started working like one hour ago. I had a small error in my code which I was easily able to fix. In the same "deploy-cycle", Firebase CLI has shown me an available update for firebase-tools suggesting me to use </p>
  
  <pre><code>npm install -g firebase-tools
  </code></pre>
  
  <p>This is what I did and where my tragedy began.
  CLI then recommended to uninstall/reinstall </p>
  
  <pre><code>    npm uninstall -g @google-cloud/functions-emulator
      npm install -g @google-cloud/functions-emulator
  </code></pre>
  
  <p>So I did.
  Then I tried to deploy my functions (from local index.js) and received the following waring:</p>
  
  <p><strong>Error: Firebase config variables are not available. Please use the latest version of the Firebase CLI to deploy this function</strong></p>
  
  <p>I used <code>npm install -g firebase-tools</code> in order to update firebase CLI but nothing changed.</p>
  
  <p>I thought it would be a good idea to just backup my old project and initialize a new one in a new folder and to connect it to my existing FB-Project and just copy-paste my the content of my old index.js to the one in the new project folder.
  Trying to deploy this new project, I received a ton of errors and warning concerning my code, like:</p>
  
  <pre><code>18:4   error    Expected catch() or return                  promise/catch-or-return
  </code></pre>
  
  <p>and many more, even though my coded functions worked fine before.</p>
  
  <p>So I decided that it would probably be the best to try and fix the error with the old project.</p>
  
  <p>Does anyone have a recommendation what to do in this case or where to find these mysterious firebase config variables? I wasn't able to find any solution to my problem online.
  I'd really appreciate any kind of helping support, since I have no idea what to do and I have no support from my university doing this...</p>