Question

A common pattern in my Express app is to include the following in all my routes:

//...code which could result in an err
if (!err) return res.send(200);
console.log(err); // Would prefer to omit this line
res.send(500);

Right now, I need to write console.log(err) in all my routes. I’d prefer to just automatically log the err variable every time a 500 is sent. Is there any way to hook into Express and automatically log the call stack and/or err for all 500 responses?

Answer 1

From your explanation, you seem to be including error handling in all your routes.
You probably should create a global interceptor error handler which can perform the logging for you and still be the base error handler if you have a 500 error type.

//if your express var is app

var errorHandler = function(err, req, res, next){
   console.log(err.stack);
   res.send(500);
   // or you could call res.render('error'); if you have a view for that.
};

app.use(app.router); // this has to come before your interceptors
app.use(notFound);  // your page not found interceptor
app.use(errorHandler);