Getting a error after setting up the whole app now

To finally help you with this, it all comes down to one word. It's so crazy how just one little error can cause such a wild goose chase! Let me walk you through how I found this error:

1. Google
   • I googled the error code and found this stackoverflow which led me to believe there might be a problem with one of the res.redirect()s.
2. Identifying when the error occurs while navigating the app
   • By taking note of every time the error was being thrown, I realized it was every time a card was being navigated to. This lead me to believe the problem is probably with a route in the cards.js file because:
   • The error was thrown on card navigation, so it is happening whenever the route is changing.
   • It's happening only in relation to the cards and cards.js is where all of those routes are written. (Great job with code organization by the way!)
3. More research!
   • I evaluated your code and realized that one of your res.redirect()s had return in front and one did not, meaning one of your code blocks were finished and the other could be left open potentially.
   • Adding the return piece of code will ensure it runs exactly as expected, whereas not including it could leave it a little more wiggle room.
   • I then did some more googling about return res.redirect() and found this stackoverflow which isn't the best article ever, but it details your same code structure. (There are definitely more instances you could find of this if you google "return res.redirect" if this specific one doesn't speak to you)
4. Implemented a potential solution based on my research SOLUTION BELOW
   • I decided to change line 18 in cards.js to be a return statement and ran the app.
   • In cards.js line 18 now reads in full as:

    return res.redirect(`/cards/${id}?side=question`);

Now we test the app!

• After changing line 18 to be a return statement, I then went through each route where an error was previously thrown and checked to make sure that no errors occurred now.
• I also took the opportunity to check that the rest of the app is still functioning as expected.

And voila! Your app should now work as intended and not throw any errors. You did a great job of following along with the lesson and I truly thank you for your patience while waiting for an answer to this minor fix. Please let my know if you have any further questions! I'm keeping my eye on this discussion so that you don't have to wait weeks for another answer :)