Reduce flakiness in chrome_frame_tests.exe by having each run in a clean environment.

chrome_frame/test/test_scrubber.cc

Index: chrome_frame/test/test_scrubber.cc
diff --git a/chrome_frame/test/test_scrubber.cc b/chrome_frame/test/test_scrubber.cc
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index 0000000000000000000000000000000000000000..1ec29ec10f14935dd706c74e8b9126d3f40b83e4
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+++ b/chrome_frame/test/test_scrubber.cc
@@ -0,0 +1,144 @@
+// Copyright (c) 2012 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.
+
+// The test scrubber uses a Google Test event listener to trigger scrubs.
+// Scrubs are performed at the start of the test program and at the conclusion
+// of each test.
+
+#include "chrome_frame/test/test_scrubber.h"
+
+#include <windows.h>
+
+#include "base/compiler_specific.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/process_util.h"
+#include "base/string16.h"
+#include "base/utf_string_conversions.h"
+#include "base/win/registry.h"
+#include "base/win/scoped_handle.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome_frame/test/chrome_frame_test_utils.h"
+#include "content/public/common/content_switches.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chrome_frame_test {
+
+namespace {

[robertshield, 2012/02/27 21:13:42]

nit: dunno if we should nest anonymous namespaces, I usually see them at the top
of the file. no strong opinion though and the style guide doesn't specify.

[grt (UTC plus 2), 2012/02/28 03:12:04]

I did the nesting here so that the contents of this unnamed namespace can access
other items in chrome_frame_test without qualifying.  I think it's a good thing,
but I'll move it up if you think it makes things less (rather than more)
readable.

[robertshield, 2012/02/28 03:32:15]

Nah, as-is is fine.

+
+class TestScrubber {
+ public:
+  TestScrubber();
+  ~TestScrubber();
+
+  // Initializes the instance, causing it to provide its services for all
+  // subsequent tests.
+  void Initialize(testing::UnitTest* unit_test);
+
+  // Sets the user data directory for the current test.
+  void set_data_directory_override(const base::StringPiece16& user_data_dir) {
+    user_data_dir.as_string().swap(data_directory_override_);
+  }
+
+  // Kills all instances of IE and all instances of chrome.exe that have
+  // --chrome-frame on their command-lines.  Also deletes the user data
+  // directory used by the test.  Ordinarily, this is the default Chrome Frame
+  // user data directory for IE.  Individual tests that use a specific directory
+  // can override this via |set_data_directory_override|.
+  void CleanUpFromTestRun();
+
+ private:
+  // A listener that calls back to the scrubber at the start of the test program
+  // and at the end of each test.
+  class EventListener : public testing::EmptyTestEventListener {
+   public:
+    explicit EventListener(TestScrubber* scrubber) : scrubber_(scrubber) {
+    }
+
+    virtual void OnTestProgramStart(const testing::UnitTest&) OVERRIDE {
+      scrubber_->CleanUpFromTestRun();
+    }
+
+    virtual void OnTestEnd(const testing::TestInfo&) OVERRIDE {
+      scrubber_->CleanUpFromTestRun();
+    }
+
+   private:
+    TestScrubber* scrubber_;
+    DISALLOW_COPY_AND_ASSIGN(EventListener);
+  };
+
+  bool is_initialized() const { return !default_data_directory_.empty(); }
+
+  string16 default_data_directory_;
+  string16 data_directory_override_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestScrubber);
+};
+
+TestScrubber::TestScrubber() {
+}
+
+TestScrubber::~TestScrubber() {
+}
+
+void TestScrubber::Initialize(testing::UnitTest* unit_test) {
+  DCHECK(!is_initialized());
+
+  default_data_directory_ = GetProfilePathForIE().value();
+  data_directory_override_.clear();
+  unit_test->listeners().Append(new EventListener(this));
+}
+
+void TestScrubber::CleanUpFromTestRun() {
+  // Kill all iexplore.exe and ieuser.exe processes.
+  base::KillProcesses(chrome_frame_test::kIEImageName, 0, NULL);
+  base::KillProcesses(chrome_frame_test::kIEBrokerImageName, 0, NULL);
+
+  // Kill all chrome_launcher processes trying to launch Chrome.
+  base::KillProcesses(chrome_frame_test::kChromeLauncher, 0, NULL);
+
+  // Kill all chrome.exe processes with --chrome-frame.
+  KillAllNamedProcessesWithArgument(
+      chrome::kBrowserProcessExecutableName,
+      ASCIIToWide(switches::kChromeFrame));
+
+  // Delete the user data directory.
+  string16& data_directory = data_directory_override_.empty() ?
+      default_data_directory_ :
+      data_directory_override_;
+
+  VLOG_IF(1, file_util::PathExists(FilePath(data_directory)))
+      << __FUNCTION__ << " deleting user data directory " << data_directory;
+  bool deleted = file_util::Delete(data_directory, true);
+  LOG_IF(ERROR, !deleted)
+      << "Failed to delete user data directory directory " << data_directory;
+
+  // Clear the overridden data directory for the next test.
+  data_directory_override_.clear();
+}
+
+base::LazyInstance<TestScrubber> g_scrubber = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+void InstallTestScrubber(testing::UnitTest* unit_test) {
+  // Must be called before running any tests.
+  DCHECK(unit_test);
+  DCHECK(!unit_test->current_test_case());
+
+  g_scrubber.Get().Initialize(unit_test);
+}
+
+void OverrideDataDirectoryForThisTest(
+    const base::StringPiece16& user_data_dir) {
+  // Must be called within the context of a test.
+  DCHECK(testing::UnitTest::GetInstance()->current_test_info());
+
+  g_scrubber.Get().set_data_directory_override(user_data_dir);
+}
+
+}  // namespace chrome_frame_test