Added options to change log

.gitignore

@@ -5,3 +5,4 @@
 
 node_modules
 coverage
+.idea

README.md

@@ -30,7 +30,16 @@ app.use('/api', api);
 
 ### .use(errorHandler([options]))
 
-Currently no options.
+Returns middleware that handle errors.
+
+#### Options
+
+The `errorHandler` function takes an option `options` object that may contain any of
+the following keys:
+
+##### log
+
+The `log` option, if supplied, is called as `log(err, req, res)` when errors with status 500 and above occur.
 
 ### Errors
 

index.js

@@ -3,7 +3,14 @@ var statuses = require('statuses');
 
 var production = process.env.NODE_ENV === 'production';
 
-module.exports = function () {
+var defaultLog = function (err) {
+  console.error(err.stack);
+};
+
+module.exports = function (options) {
+  var opts = options || {};
+  var log = opts.log || defaultLog;
+
   return function apiErrorHandler(err, req, res, next) {
     var status = err.status || err.statusCode || 500;
     if (status < 400) status = 500;
@@ -19,7 +26,7 @@ module.exports = function () {
 
     // internal server errors
     if (status >= 500) {
-      console.error(err.stack);
+      log(err, req, res);
       body.message = statuses[status];
       res.json(body);
       return;