Fixes #2888 - Retry on network error (#4959)

* Fixes #2888 - Retry on network error

Retry failed network requests 3 times in the JS bindings like Ruby.
The previous 15 ms timeout was kept though, unlike the 2s sleep from Ruby.
Credit goes to @JosephGarrone for the workaround and @p0deje for finding the
Ruby http module.

javascript/node/selenium-webdriver/http/index.js

@@ -144,8 +144,9 @@ class HttpClient {
  * @param {function(!Error)} onError The function to call if the request fails.
  * @param {?string=} opt_data The data to send with the request.
  * @param {?RequestOptions=} opt_proxy The proxy server to use for the request.
+ * @param {number=} opt_retries The current number of retries.
  */
-function sendRequest(options, onOk, onError, opt_data, opt_proxy) {
+function sendRequest(options, onOk, onError, opt_data, opt_proxy, opt_retries) {
   var hostname = options.hostname;
   var port = options.port;
 
@@ -161,7 +162,7 @@ function sendRequest(options, onOk, onError, opt_data, opt_proxy) {
     // An HTTP/1.1 proxy MUST ensure that any request message it forwards does
     // contain an appropriate Host header field that identifies the service
     // being requested by the proxy.
-    let targetHost = options.hostname
+    let targetHost = options.hostname;
     if (options.port) {
       targetHost += ':' + options.port;
     }
@@ -226,9 +227,14 @@ function sendRequest(options, onOk, onError, opt_data, opt_proxy) {
   });
 
   request.on('error', function(e) {
-    if (e.code === 'ECONNRESET') {
+    if (typeof opt_retries === 'undefined') {
+      opt_retries = 0;
+    }
+
+    if (shouldRetryRequest(opt_retries, e)) {
+      opt_retries += 1;
       setTimeout(function() {
-        sendRequest(options, onOk, onError, opt_data, opt_proxy);
+        sendRequest(options, onOk, onError, opt_data, opt_proxy, opt_retries);
       }, 15);
     } else {
       var message = e.message;
@@ -247,6 +253,36 @@ function sendRequest(options, onOk, onError, opt_data, opt_proxy) {
 }
 
 
+const MAX_RETRIES = 3;
+
+/**
+ * A retry is sometimes needed on Windows where we may quickly run out of
+ * ephemeral ports. A more robust solution is bumping the MaxUserPort setting
+ * as described here: http://msdn.microsoft.com/en-us/library/aa560610%28v=bts.20%29.aspx
+ *
+ * @param {!number} retries
+ * @param {!Error} err
+ * @return {boolean}
+ */
+function shouldRetryRequest(retries, err) {
+  return retries < MAX_RETRIES && isRetryableNetworkError(err);
+}
+
+/**
+ * @param {!Error} err
+ * @return {boolean}
+ */
+function isRetryableNetworkError(err) {
+  if (err && err.code) {
+    return err.code === 'ECONNABORTED' ||
+          err.code === 'ECONNRESET' ||
+          err.code === 'EADDRINUSE';
+  }
+
+  return false;
+}
+
+
 // PUBLIC API
 
 exports.Executor = httpLib.Executor;