Beef up XHR code in sh.wget(), still failing 2 in PhantomJS due to not having web server

src/shell/shell.js

@@ -444,8 +444,16 @@ define(function(require) {
     var path = options.filename || ('file-' + Date.now());
     path = Path.resolve(fs.cwd, path);
 
+    function onerror() {
+     callback(new Error('unable to get resource'));
+    }
+
     var request = new XMLHttpRequest();
-    request.addEventListener("load", function() {
+    request.onload = function() {
+      if(request.status !== 200) {
+        return onerror();
+      }
+
       var data = new Uint8Array(request.response);
       fs.writeFile(path, data, function(err) {
         if(err) {
@@ -454,9 +462,12 @@ define(function(require) {
           callback(null, path);
         }
       });
-    }, false);
-    request.addEventListener("error", function(err) { callback(err); }, false);
-    request.open("GET", url);
+    };
+    request.onerror = onerror;
+    request.open("GET", url, true);
+    if("withCredentials" in request) {
+      request.withCredentials = true;
+    }
     request.responseType = "arraybuffer";
     request.send();
   };

tests/spec/shell/wget.spec.js

@@ -20,6 +20,17 @@ define(["Filer", "util"], function(Filer, util) {
       });
     });
 
+    it('should fail when the url does not exist (404)', function(done) {
+      var fs = util.fs();
+      var shell = fs.Shell();
+
+      shell.wget("no-such-url", function(err, data) {
+        expect(err).to.exist;
+        expect(data).not.to.exist;
+        done();
+      });
+    });
+
     it('should download the contents of a file from a url to default filename', function(done) {
       var fs = util.fs();
       var shell = fs.Shell();