Fix exceptions when running the tests.

Tools/GardeningServer/scripts/net_unittests.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // Export NetworkSimulator for use by other unittests.
 function NetworkSimulator()
 {
     this._pendingPromises = [];
 };
 
+NetworkSimulator._testInProgress = false;
+
 NetworkSimulator.prototype.schedulePromise = function(promise) {
     this._pendingPromises.push(promise);
     return promise;
 };
 
 NetworkSimulator.prototype.resolvePromises = function() {
     var self = this;
     return new Promise(function(resolve, reject) {
         var pendingPromises = self._pendingPromises;
         self._pendingPromises = [];
-        function all_resolved (results) {
+        function allResolved(results) {
             if (self._pendingPromises.length) {
                 resolve(self.resolvePromises());
                 return;
             }
             resolve(results);
         }
-        Promise.all(pendingPromises).then(all_resolved, all_resolved);
+        Promise.all(pendingPromises).then(allResolved, allResolved);
     });
 };
 
 NetworkSimulator.prototype.runTest = function(testCase)
 {
+    if (NetworkSimulator._testInProgress) {
+        ok(false, "runTest calls cannot be nested");
+        start();
+        return;
+    }
+
+    NetworkSimulator._testInProgress = true;
+
     var self = this;
-    var realNet = window.net;
     return new Promise(function(resolve, reject) {
+        var realNet = window.net;
+
+        function reset() {
+            window.net = realNet;
+            NetworkSimulator._testInProgress = false;
+        }
 
         // All net.* methods should return promises. This watches all
         // promises generated by test-overridden methods.
         window.net = {};
         ['probe', 'jsonp', 'get', 'post',
          'ajax', 'json', 'xml'].forEach(function(method) {
-             if (method in self) {
-                 net[method] = function() {
-                     return self.schedulePromise(self[method].apply(self, arguments));
-                 };
-             };
-         });
+            if (method in self) {
+                net[method] = function() {
+                    return self.schedulePromise(self[method].apply(self, arguments));
+                };
+            };
+        });
 
-        testCase();
+        try {
+            testCase();
+        } catch(e) {
+            // Make sure errors thrown in the test case don't leave window.net in a bad state.
+            reset();
+            ok(false, "Test case threw an error:" + e);
+        }
+
         self.resolvePromises().then(function() {
-            window.net = realNet;
+            reset();
             equal(window.net, realNet);
             resolve();
         }).catch(function(e) {
+            reset();
             ok(false, "Failed to finish test: " + e);
         });
     });
 };
 
 (function () {
 
 module("net");
 
 test("parseJSONP", 6, function() {
     deepEqual(net._parseJSONP(""), {});
     deepEqual(net._parseJSONP('p({"key": "value"})'), {"key": "value"});
     deepEqual(net._parseJSONP('ADD_RESULTS({"dummy":"data"});'), {"dummy":"data"});
     deepEqual(net._parseJSONP('{"dummy":"data"}'), {"dummy":"data"});
     deepEqual(net._parseJSONP('ADD_RESULTS({"builder(1)":"data"});'), {"builder(1)":"data"});
     deepEqual(net._parseJSONP('{"builder(1)":"data"}'), {"builder(1)":"data"});
 });
 
 })();