Added timeout feature

lib/XMLHttpRequest.js

@@ -115,6 +115,24 @@ exports.XMLHttpRequest = function() {
   // Whether cross-site Access-Control requests should be made using
   // credentials such as cookies or authorization headers
   this.withCredentials = false;
+
+  // Number of milliseconds a request can take before automatically
+  // being terminated. Defaults to 0.
+  this._timeout = 0;
+
+  // Setting getter and setter to "timeout" field to intercept
+  // attributions. This is needed to treat the case in which
+  // the timout value is set after opening the connection
+  Object.defineProperty(this, "timeout", {
+    set: function(val) {
+      if (val > 0 && settings.async === false) {
+        throw new Error('InvalidAccessError: synchronous XMLHttpRequests do not support timeout and responseType.');
+      }
+
+      this._timeout = val;
+    },
+    get: function() { return this._timeout; }
+  });
 
   /**
    * Private methods
@@ -157,6 +175,11 @@ exports.XMLHttpRequest = function() {
     this.abort();
     errorFlag = false;
 
+    // timeout cannot be set on synchronous requests
+    if (!async && this._timeout !== 0) {
+      throw new Error('InvalidAccessError: synchronous XMLHttpRequests do not support timeout and responseType.');
+    }
+
     // Check for valid request method
     if (!isAllowedHttpMethod(method)) {
       throw new Error("SecurityError: Request method not allowed");
@@ -382,7 +405,8 @@ exports.XMLHttpRequest = function() {
       method: settings.method,
       headers: headers,
       agent: false,
-      withCredentials: self.withCredentials
+      withCredentials: self.withCredentials,
+      timeout: this._timeout
     };
 
     // Reset error flag
@@ -419,11 +443,14 @@ exports.XMLHttpRequest = function() {
             path: url.path,
             method: response.statusCode === 303 ? "GET" : settings.method,
             headers: headers,
-            withCredentials: self.withCredentials
+            withCredentials: self.withCredentials,
+            timeout: this._timeout
           };
 
           // Issue the new request
-          request = doRequest(newOptions, responseHandler).on("error", errorHandler);
+          request = doRequest(newOptions, responseHandler)
+              .on("error", errorHandler)
+              .on("timeout", timeoutHandler);
           request.end();
           // @TODO Check if an XHR event needs to be fired here
           return;
@@ -463,8 +490,17 @@ exports.XMLHttpRequest = function() {
         self.handleError(error);
       };
 
+      // Timeout handler for the request
+      var timeoutHandler = function timeoutHandler() {
+        // we need to abort the request manually
+        request.abort();
+        self.timeoutHandler();
+      }
+
       // Create the request
-      request = doRequest(options, responseHandler).on("error", errorHandler);
+      request = doRequest(options, responseHandler)
+          .on("error", errorHandler)
+          .on("timeout", timeoutHandler);
 
       // Node 0.4 and later won't accept empty data. Make sure it's needed.
       if (data) {
@@ -525,6 +561,18 @@ exports.XMLHttpRequest = function() {
     }
   };
 
+  /**
+   * Called when a timeout event is fired.
+   */
+  this.timeoutHandler = function() {
+    this.status = 0;
+    this.statusText = '';
+    this.responseText = '';
+    errorFlag = true;
+    setState(this.DONE);
+    this.dispatchEvent('timeout');
+  }
+
   /**
    * Called when an error is encountered to deal with it.
    */

tests/test-timeout.js

@@ -0,0 +1,47 @@
+var sys = require("util")
+  , assert = require("assert")
+  , http = require('http')
+  , XMLHttpRequest = require("../lib/XMLHttpRequest").XMLHttpRequest;
+
+// Test server
+http.createServer(function (req, res) {
+  setTimeout(() => {
+    res.end();
+    this.close();
+  }, 3000);
+}).listen(8000);
+
+var xhr = new XMLHttpRequest();
+// Testing simple timeout case
+xhr.open("GET", "http://localhost:8000/nowhere");
+xhr.timeout = 1000;
+
+xhr.ontimeout = function () {
+  console.log('Request timed out!');
+}
+
+xhr.send(null);
+
+// Testing when timeout is set on a sync request
+// Should throw an Error
+xhr = new XMLHttpRequest();
+xhr.open("GET", "http://localhost:8000/nowhere", false);
+
+try {
+  xhr.timeout = 1000;
+} catch (e) {
+  console.log(e.message);
+  assert.equal(e.message, 'InvalidAccessError: synchronous XMLHttpRequests do not support timeout and responseType.');
+}
+
+// Should also throw an Error if the timeout is set
+// before xhr.open() on a sync request
+xhr = new XMLHttpRequest();
+xhr.timeout = 1000;
+
+try {
+  xhr.open("GET", "http://localhost:8000/nowhere", false);
+} catch (e) {
+  console.log(e.message);
+  assert.equal(e.message, 'InvalidAccessError: synchronous XMLHttpRequests do not support timeout and responseType.');
+}