For unit tests, track additions to AtExitManager and warn.

While trying to bullet proof a unit test, I had trouble getting very far when
running all tests in shuffle mode. Tracked that back to a few other tests doing
stuff that accessed Singleton()s outside of a test-scoped
ShadowingAtExitManager. Seemed to me that should be an invariant around any
unit test, so created this towards that end, hopefully helping stabilize out
unit_tests a bit more.

BUG=133403


Review URL: https://chromiumcodereview.appspot.com/10582012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144488 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 56 insertions, 0 deletions

diff --git a/base/test/test_suite.cc b/base/test/test_suite.cc
index fb0070f..67ea0a4 100644
--- a/base/test/test_suite.cc
+++ b/base/test/test_suite.cc
@@ -17,6 +17,7 @@
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/test/multiprocess_test.h"
+#include "base/test/test_switches.h"
 #include "base/test/test_timeouts.h"
 #include "base/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -69,6 +70,46 @@ class TestClientInitializer : public testing::EmptyTestEventListener {
 
 }  // namespace
 
+namespace base {
+
+class TestWatchAtExitManager : public testing::EmptyTestEventListener {
+ public:
+  TestWatchAtExitManager() { }
+  ~TestWatchAtExitManager() { }
+
+  virtual void OnTestStart(const testing::TestInfo& test_info) OVERRIDE {
+    initial_top_manager_ = AtExitManager::current();
+    at_exit_stack_size_ = initial_top_manager_->CallbackStackSize();
+  }
+
+  virtual void OnTestEnd(const testing::TestInfo& test_info) OVERRIDE {
+    AtExitManager* new_top_manager = AtExitManager::current();
+    size_t new_stack_size = new_top_manager->CallbackStackSize();
+
+    if (initial_top_manager_ != new_top_manager) {
+      ADD_FAILURE() << "The current AtExitManager has changed across the "
+          "test " << test_info.test_case_name() << "." << test_info.name() <<
+          " most likely because one was created without being destroyed.";
+    } else if (new_stack_size != at_exit_stack_size_) {
+      // TODO(scottbyer): clean up all the errors that result from this and
+      // turn this into a test failure with
+      // ADD_FAILURE(). http://crbug.com/133403
+      LOG(WARNING) <<
+          "AtExitManager: items were added to the callback list by " <<
+          test_info.test_case_name() << "." << test_info.name() <<
+          ". Global state should be cleaned up before a test exits.";
+    }
+  }
+
+ private:
+  AtExitManager* initial_top_manager_;
+  size_t at_exit_stack_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestWatchAtExitManager);
+};
+
+}  // namespace base
+
 const char TestSuite::kStrictFailureHandling[] = "strict_failure_handling";
 
 TestSuite::TestSuite(int argc, char** argv) : initialized_command_line_(false) {
@@ -170,6 +211,12 @@ void TestSuite::ResetCommandLine() {
   listeners.Append(new TestClientInitializer);
 }
 
+void TestSuite::WatchAtExitManager() {
+  testing::TestEventListeners& listeners =
+      testing::UnitTest::GetInstance()->listeners();
+  listeners.Append(new TestWatchAtExitManager);
+}
+
 // Don't add additional code to this method.  Instead add it to
 // Initialize().  See bug 6436.
 int TestSuite::Run() {
@@ -287,6 +334,15 @@ void TestSuite::Initialize() {
   CatchMaybeTests();
   ResetCommandLine();
 
+  // Don't watch for AtExit items being added if we're running as a child
+  // process (e.g., browser_tests or interactive_ui_tests).
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kSingleProcessTestsFlag) &&
+      !CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kSingleProcessChromeFlag)) {
+    WatchAtExitManager();
+  }
+
   TestTimeouts::Initialize();
 }