filter some nasty errors

Related to #119 and #156

index.js

@@ -1,4 +1,5 @@
 'use strict';
+
 var EventEmitter = require('events').EventEmitter;
 var http = require('http');
 var https = require('https');
@@ -19,6 +20,7 @@ var createErrorClass = require('create-error-class');
 var nodeStatusCodes = require('node-status-codes');
 var isPlainObj = require('is-plain-obj');
 var parseJson = require('parse-json');
+var isRetryAllowed = require('is-retry-allowed');
 
 function requestAsEventEmitter(opts) {
 	opts = opts || {};
@@ -271,8 +273,8 @@ function normalizeArguments(url, opts) {
 
 	if (typeof opts.retries !== 'function') {
 		var retries = opts.retries;
-		opts.retries = function backoff(iter) {
-			if (iter > retries) {
+		opts.retries = function backoff(iter, err) {
+			if (iter > retries || !isRetryAllowed(err)) {
 				return 0;
 			}
 

package.json

@@ -49,6 +49,7 @@
     "duplexer2": "^0.1.4",
     "is-plain-obj": "^1.0.0",
     "is-redirect": "^1.0.0",
+    "is-retry-allowed": "^1.0.0",
     "is-stream": "^1.0.0",
     "lowercase-keys": "^1.0.0",
     "node-status-codes": "^1.0.0",