Fixing the Route.post() requires a callback function but got a [object Promise] Error in Express.js

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Understanding the Problem

Scenario Breakdown

For example, if you follow a controller structure like this:

[[See Video to Reveal this Text or Code Snippet]]

Here, wrapRoute is designed to handle errors and run your asynchronous logic. However, if wrapRoute itself returns a Promise, Express will reject it as a valid callback.

The Solution

Step 1: Modify the EmailLogin Function

To fix this issue, you can modify your EmailLogin function as follows:

Convert the wrapRoute Usage: Instead of using wrapRoute to wrap your async logic, directly handle errors within the EmailLogin function itself.

Change the Signature: Make sure your function matches the expected format for Express handlers, which means it should accept req, res, and next arguments.

Updated Code Example

Here's how you can restructure your EmailLogin function:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Router Setup

Make sure your router setup correctly calls the updated EmailLogin controller:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

With these adjustments, you not only fix the error but also adhere to best practices in error handling within your Express application. Happy coding!