ExpressJS writes deprecation warnings into the application's stderr:
express deprecated res.send(status): Use res.status(status).end() instead
This triggers false alarms if you use log monitoring for the error output. This is not desired in the production environment where you want focus on the actual errors. These messages are not silenced by using the
NODE_ENV=production environment variable. To silence them, you also need to set the
NO_DEPRECATION=express environment variable.
The best solution is to replace
res.send calls but sometimes this is not easy for a larger application or for an application that uses external 3rd party packages that use
More information: https://github.com/strongloop/express/issues/2392.