Allow for root configurations

index.js

@@ -1,3 +1,4 @@
+exports.config = require('./lib/config');
 exports.Client = require('./lib/client');
 exports.Dispatcher = require('./lib/dispatcher');
 exports.auth = require('./lib/auth');

lib/config/index.js

@@ -0,0 +1,9 @@
+var errors = require('../errors');
+
+var config = {};
+
+config.setConfig = function(errorName, errorConfig) {
+    errors[errorName].config = errorConfig;
+};
+
+module.exports = config;

lib/dispatcher.js

@@ -260,7 +260,9 @@ Dispatcher.prototype.dispatch = function(params, dispatchOptions) {
         }
 
         if (STATUS_MAP[res.statusCode]) {
-          var error = new STATUS_MAP[res.statusCode](payload, res);
+          var errorConfig = STATUS_MAP[res.statusCode].config;
+          var args = Object.assign({}, payload, errorConfig);
+          var error = new STATUS_MAP[res.statusCode](args, res);
 
           if (me.retryOnRateLimit &&
               error instanceof (errors.RateLimitEnforced)) {

lib/errors/rate_limit_enforced.js

@@ -14,4 +14,4 @@ function RateLimitEnforced(value, res) {
 
 util.inherits(RateLimitEnforced, Error);
 
-module.exports = RateLimitEnforced;
+module.exports = RateLimitEnforced;