title: Service/data layer exception handling in express validator
body: <p>Ive built an app that pipes requests through express validator's validation chains, but I ran into a design issue related to logging and error handling.</p>
  <p>My app is divided into distinct controllers/services/repositories. All errors thrown in repos and layers bubble up to controllers which handle errors by calling next() on them and passing them to an error handling middleware that logs and so on.</p>
  <p>The problem is that one of my validation chains calls a repo. If my DB connection is dead, all I get on my log is what I happen to put in the validation chain's withMessage().</p>
  <p>Id like to get a better log of the event in such case, but now a dead db connection ends in a 400 Bad request on the logs since there isnt a controller to catch the error.</p>
  <p>Any ideas how I should structure my app to combat this?</p>
  <p>I would not like to add specific logging on the service/data layers only because I use express validator as a middleware.</p>