[chromedriver] Implement command: executeAsyncScript and setScriptTimeout

chrome/test/chromedriver/js/execute_async_script.js

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+* Return the information of asynchronous script execution.
+*
+* @return {Object.<string, ?>} Information of asynchronous script execution.
+*/
+function getAsyncScriptInfo() {
+  var key = 'chromedriverAsyncScriptInfo';
+  if (!(key in document))
+    document[key] = {'id': 0, 'finished': false};
+  return document[key];
+}
+
+/**
+* Execute the given script and save its asynchronous result.
+*
+* If script1 finishes after script2 is executed, then script1's result will be
+* discarded while script2's will be saved.
+*
+* @param {!string} script The asynchronous script to be executed.
+* @param {Array.<*>} args Arguments to be passed to the script.
+* @param {!number} timeout The timeout for the asynchronous script.
+*/
+function executeAsyncScript(script, args, timeout) {
+  var info = getAsyncScriptInfo();
+  info['id']++;

[kkania, 2013/03/08 21:56:50]

instead of info['id'] style, do info.id; same for other cases

[chrisgao (Use stgao instead), 2013/03/08 23:28:25]

Done.

+  info['finished'] = false;
+  delete info['result'];
+  var id = info['id'];
+
+  function callback(result) {
+    if (id == info['id']) {
+      info['result'] = result;

[kkania, 2013/03/08 21:56:50]

there's still a small bug where this will hold a reference to the result if the
script times out but the result is set after the timeout.

[chrisgao (Use stgao instead), 2013/03/08 23:28:25]

Done.

+      info['finished'] = true;
+    }
+  }
+  args.push(callback);
+
+  try {
+    new Function(script).apply(null, args);
+  } catch (error) {
+    error.code = 17;  // Error code for JavaScriptError.
+    throw error;
+  }
+
+  // If timeout is 0 and callback is not called synchronously, raise a
+  // ScriptTimeout error.
+  if (timeout == 0 && !info['finished']) {

[chrisgao (Use stgao instead), 2013/03/08 23:28:25]

Removed, because this failed one java test.

executeAsyncScript {"script":"var callback = arguments[arguments.length -
1];window.setTimeout(function() { callback(123); }, 0)","args":[]}

And now we pass all java test on command executeAsyncScript.

+    info['id']++;  // Avoid the asynchronous script to set the result.
+    var error = new Error();
+    error.code = 28;  // Error code for ScriptTimeout.
+    throw error;
+  }
+}