Bound the impact of system instability on chrome instability.

components/browser_watcher/system_session_analyzer_win_unittest.cc

+// Copyright 2017 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 "components/browser_watcher/system_session_analyzer_win.h"
+
+#include <utility>
+#include <vector>
+
+#include "base/time/time.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace browser_watcher {
+
+namespace {
+
+const uint16_t kIdSessionStart = 6005U;
+const uint16_t kIdSessionEnd = 6006U;
+const uint16_t kIdSessionEndUnclean = 6008U;
+
+}  // namespace
+
+// Ensure the fetcher retrieves events.
+// Note: this test fails if the host system doesn't have at least 1 prior
+// session.
+TEST(SystemSessionEventFetcherTest, TestRetrieval) {
+  SystemSessionEventFetcher fetcher(1);
+  std::vector<SystemSessionEventFetcher::EventInfo> events;
+  ASSERT_TRUE(fetcher.FetchEvents(&events));
+  EXPECT_EQ(3U, events.size());
+}
+
+// Ensure the fetcher's retrieved events conform to our expectations. This
+// conformance is validated using the SystemSessionAnalyzer. Note that the
+// ability of SystemSessionAnalyzer to validate the conformance is tested below.
+// Note: this test fails if the host system doesn't have at least 1 prior
+// session.
+TEST(SystemSessionEventFetcherTest, NoEvent) {
+  SystemSessionEventFetcher fetcher(1U);
+  SystemSessionAnalyzer analyzer(&fetcher);
+  EXPECT_EQ(SystemSessionAnalyzer::CLEAN,
+            analyzer.IsSessionUnclean(base::Time::Now()));
+}
+
+class StubSystemSessionEventFetcher : public SystemSessionEventFetcher {
+ public:
+  StubSystemSessionEventFetcher() : SystemSessionEventFetcher(10U) {}
+
+  bool FetchEvents(std::vector<EventInfo>* event_infos) const override {
+    DCHECK(event_infos);
+    *event_infos = events_;
+    return true;
+  }
+
+  void AddEvent(const EventInfo& info) { events_.push_back(info); }
+
+ private:
+  std::vector<EventInfo> events_;
+};
+
+TEST(SystemSessionAnalyzerTest, StandardCase) {
+  StubSystemSessionEventFetcher fetcher;
+
+  base::Time time = base::Time::Now();
+  fetcher.AddEvent({kIdSessionStart, time});
+  fetcher.AddEvent(
+      {kIdSessionEndUnclean, time - base::TimeDelta::FromSeconds(10)});
+  fetcher.AddEvent({kIdSessionStart, time - base::TimeDelta::FromSeconds(20)});
+  fetcher.AddEvent({kIdSessionEnd, time - base::TimeDelta::FromSeconds(22)});
+  fetcher.AddEvent({kIdSessionStart, time - base::TimeDelta::FromSeconds(28)});
+
+  SystemSessionAnalyzer analyzer(&fetcher);
+
+  EXPECT_EQ(SystemSessionAnalyzer::OUTSIDE_RANGE,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(30)));
+  EXPECT_EQ(SystemSessionAnalyzer::CLEAN,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(25)));
+  EXPECT_EQ(SystemSessionAnalyzer::UNCLEAN,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(20)));
+  EXPECT_EQ(SystemSessionAnalyzer::UNCLEAN,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(15)));
+  EXPECT_EQ(SystemSessionAnalyzer::UNCLEAN,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(10)));
+  EXPECT_EQ(SystemSessionAnalyzer::CLEAN,
+            analyzer.IsSessionUnclean(time - base::TimeDelta::FromSeconds(5)));
+  EXPECT_EQ(SystemSessionAnalyzer::CLEAN,
+            analyzer.IsSessionUnclean(time + base::TimeDelta::FromSeconds(5)));
+}
+
+TEST(SystemSessionAnalyzerTest, NoEvent) {
+  StubSystemSessionEventFetcher fetcher;
+  SystemSessionAnalyzer analyzer(&fetcher);
+  EXPECT_EQ(SystemSessionAnalyzer::FAILED,
+            analyzer.IsSessionUnclean(base::Time::Now()));
+}
+
+TEST(SystemSessionAnalyzerTest, TimeInversion) {
+  StubSystemSessionEventFetcher fetcher;
+
+  base::Time time = base::Time::Now();
+  fetcher.AddEvent({kIdSessionStart, time});
+  fetcher.AddEvent({kIdSessionEnd, time + base::TimeDelta::FromSeconds(1)});
+  fetcher.AddEvent({kIdSessionStart, time - base::TimeDelta::FromSeconds(1)});
+
+  SystemSessionAnalyzer analyzer(&fetcher);
+  EXPECT_EQ(SystemSessionAnalyzer::FAILED,
+            analyzer.IsSessionUnclean(base::Time::Now()));
+}
+
+TEST(SystemSessionAnalyzerTest, IdInversion) {
+  StubSystemSessionEventFetcher fetcher;
+
+  base::Time time = base::Time::Now();
+  fetcher.AddEvent({kIdSessionStart, time});
+  fetcher.AddEvent({kIdSessionStart, time - base::TimeDelta::FromSeconds(1)});
+  fetcher.AddEvent({kIdSessionEnd, time - base::TimeDelta::FromSeconds(2)});
+
+  SystemSessionAnalyzer analyzer(&fetcher);
+  EXPECT_EQ(SystemSessionAnalyzer::FAILED,
+            analyzer.IsSessionUnclean(base::Time::Now()));
+}
+
+}  // namespace browser_watcher