[chromedriver] Add a sanity check during session initiation

chrome/test/chromedriver/session_commands.cc

 // 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.
 
 #include "chrome/test/chromedriver/session_commands.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"  // For CHECK macros.
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/strings/stringprintf.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/values.h"
 #include "chrome/test/chromedriver/basic_types.h"
 #include "chrome/test/chromedriver/capabilities.h"
 #include "chrome/test/chromedriver/chrome/automation_extension.h"
 #include "chrome/test/chromedriver/chrome/browser_info.h"
 #include "chrome/test/chromedriver/chrome/chrome.h"
 #include "chrome/test/chromedriver/chrome/chrome_android_impl.h"
 #include "chrome/test/chromedriver/chrome/chrome_desktop_impl.h"
@@ skipping 73 matching lines @@
   if (status.IsOk()) {
     chrome_caps->SetString(
         "userDataDir",
         desktop->command().GetSwitchValueNative("user-data-dir"));
   }
 
   caps->Set("chrome", chrome_caps.release());
   return caps.Pass();
 }
 
+Status CheckSessionCreated(Session* session) {
+  WebView* web_view = NULL;
+  Status status = session->GetTargetWindow(&web_view);
+  if (status.IsError())
+    return Status(kSessionNotCreatedException, status);
+
+  status = web_view->ConnectIfNecessary();
+  if (status.IsError())
+    return Status(kSessionNotCreatedException, status);
+
+  base::ListValue args;
+  args.AppendString("ping");
+  scoped_ptr<base::Value> result(new base::StringValue(std::string()));
+  status = web_view->CallFunction(session->GetCurrentFrameId(),
+                                  "function(s){return s.replace('i','o')}",

[stgao, 2015/03/14 00:22:03]

For the purpose of sanity check, maybe a simple "return '1';" is good enough?

[samuong, 2015/03/14 17:17:46]

Done.

+                                  args, &result);
+  if (status.IsError())
+    return Status(kSessionNotCreatedException, status);
+
+  std::string response;
+  if (!result->GetAsString(&response) || response != "pong") {
+    return Status(kSessionNotCreatedException,
+                  base::StringPrintf("unexpected response from browser"));

[stgao, 2015/03/14 00:22:03]

It seems other places use raw strings directly, like line 146 and 189 below. Is
there a special reason to use base::StringPrintf?

[samuong, 2015/03/14 17:17:46]

Done. It's no longer needed, so I've removed it.

+  }
+
+  return Status(kOk);
+}
+
 Status InitSessionHelper(
     const InitSessionParams& bound_params,
     Session* session,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   session->driver_log.reset(
       new WebDriverLog(WebDriverLog::kDriverType, Log::kAll));
   const base::DictionaryValue* desired_caps;
   if (!params.GetDictionary("desiredCapabilities", &desired_caps))
     return Status(kUnknownError, "cannot find dict 'desiredCapabilities'");
@@ skipping 40 matching lines @@
   if (status.IsError() || web_view_ids.empty()) {
     return status.IsError() ? status :
         Status(kUnknownError, "unable to discover open window in chrome");
   }
 
   session->window = web_view_ids.front();
   session->detach = capabilities.detach;
   session->force_devtools_screenshot = capabilities.force_devtools_screenshot;
   session->capabilities = CreateCapabilities(session->chrome.get());
   value->reset(session->capabilities->DeepCopy());
-  return Status(kOk);
+  return CheckSessionCreated(session);
 }
 
 }  // namespace
 
 Status ExecuteInitSession(
     const InitSessionParams& bound_params,
     Session* session,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   Status status = InitSessionHelper(bound_params, session, params, value);
@@ skipping 506 matching lines @@
 Status ExecuteSetAutoReporting(
     Session* session,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   bool enabled;
   if (!params.GetBoolean("enabled", &enabled))
     return Status(kUnknownError, "missing parameter 'enabled'");
   session->auto_reporting_enabled = enabled;
   return Status(kOk);
 }