Capture work function exceptions and fill callbacks accordingly

lib/caching.js

@@ -1,4 +1,6 @@
 /*jshint maxcomplexity:15*/
+var domain = require('domain');
+
 var caching = function (args) {
     args = args || {};
     var self = {};
@@ -60,7 +62,12 @@ var caching = function (args) {
             } else if (result) {
                 fillCallbacks(null, result);
             } else {
-                work(function (err, data) {
+                domain
+                .create()
+                .on('error', function(err){
+                    fillCallbacks(err);
+                })
+                .bind(work)(function (err, data) {
                     if (err) {
                         fillCallbacks(err);
                         return;
@@ -69,7 +76,7 @@ var caching = function (args) {
                         if (err && (!self.ignoreCacheErrors)) {
                             fillCallbacks(err);
                         } else {
-                            fillCallbacks(null, data);
+                            fillCallbacks(err, data);
                         }
                     });
                 });

lib/multi_caching.js

@@ -1,4 +1,5 @@
 var async = require('async');
+var domain = require('domain');
 
 /**
  * Module that lets you specify a hierarchy of caches.
@@ -75,9 +76,14 @@ var multi_caching = function (caches) {
                     fillCallbacks(err, result);
                 });
             } else {
-                work(function (err, data) {
+                domain
+                .create()
+                .on('error', function(err){
+                    fillCallbacks(err);
+                })
+                .bind(work)(function (err, data) {
                     if (err) {
-                        fillCallbacks(err, null);
+                        fillCallbacks(err, data);
                         return;
                     }
                     var opts = {
@@ -86,11 +92,7 @@ var multi_caching = function (caches) {
                         ttl: ttl
                     };
                     set_in_multiple_caches(caches, opts, function (err) {
-                        if (err) {
-                            fillCallbacks(err);
-                        } else {
                         fillCallbacks(null, data);
-                        }
                     });
                 });
             }