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Strahinja Laktovic
Strahinja Laktovic

Posted on • Updated on

Error handling in Node.js Express Applications

Hello fellow devs. I thought we might share some ideas about error handling in Express applications.

The goal: Having people share all kind of ideas could help everyone reading/discussing make their own error handling or strengthen the current one.

Requirements: One should handle cases having errors being thrown in one or more services, both their own and third party library utilization ones.

My idea:

1. Creation of StatusError such as

2. Throwing this error in services that are part of our business domain with         
    meaningful statuses, such as 400, 404, 401 etc.

3. Throwing this error in services that handle consuming 3rd party API with 
    such status that has semantic meaning, even if it may be slightly different 
    from the one in API. One could also add additional info comprised of data 
    successfully computed before such error. 

    e.g. Throwing 404 while trying to find 3rd party resource connected to some 
         in our base even though third party API may throw different error but 
         with such response that corresponds 404. One could also add name of 
         resource from our base in message to help further solving the issue.

4. These errors could be caught in route handlers and sent further down the 
   pipe to error handler.

5. Error handler could call the appropriate error handling module which can do 
    multiple, separated actions, such as logging, special handling for some of 
    the errors, etc.

I'm very eager to hear your ideas.

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