Add a mechanism for collecting Rappor samples on a daily interval.

components/metrics/daily_event_unittest.cc

Index: components/metrics/daily_event_unittest.cc
diff --git a/components/metrics/daily_event_unittest.cc b/components/metrics/daily_event_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4253c1304539904ebc014fd0bd8c084294c231fa
--- /dev/null
+++ b/components/metrics/daily_event_unittest.cc
@@ -0,0 +1,96 @@
+// Copyright 2014 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/metrics/daily_event.h"
+
+#include "base/prefs/testing_pref_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace metrics {
+
+namespace {
+
+const char kTestPrefName[] = "TestPref";
+const char kTestMetricName[] = "TestMetric";
+
+class TestDailyObserver : public DailyEvent::Observer {
+ public:
+  TestDailyObserver() : fired_(false) {}
+
+  bool fired() const { return fired_; }
+
+  virtual void OnDailyEvent() OVERRIDE {
+    fired_ = true;
+  }
+
+  void Reset() {
+    fired_ = false;
+  }
+
+ private:
+  // True if this event has been observed.
+  bool fired_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestDailyObserver);
+};
+
+class DailyEventTest : public testing::Test {
+ public:
+  DailyEventTest() : event_(&prefs_, kTestPrefName, kTestMetricName) {
+    DailyEvent::RegisterPref(prefs_.registry(), kTestPrefName);
+    observer_ = new TestDailyObserver();
+    scoped_ptr<metrics::DailyEvent::Observer> p(observer_);
+    event_.AddObserver(p.Pass());
+  }
+
+ protected:
+  TestingPrefServiceSimple prefs_;
+  TestDailyObserver* observer_;
+  DailyEvent event_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DailyEventTest);
+};
+
+}  // namespace
+
+// The event should fire if the preference is not available.
+TEST_F(DailyEventTest, TestNewFires) {
+  event_.CheckInterval();
+  EXPECT_TRUE(observer_->fired());
+}
+
+// The event should fire if the preference is more than a day old.
+TEST_F(DailyEventTest, TestOldFires) {
+  base::Time last_time = base::Time::Now() - base::TimeDelta::FromHours(25);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  event_.CheckInterval();
+  EXPECT_TRUE(observer_->fired());
+}
+
+// The event should fire if the preference is more than a day in the future.
+TEST_F(DailyEventTest, TestFutureFires) {
+  base::Time last_time = base::Time::Now() + base::TimeDelta::FromHours(25);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  event_.CheckInterval();
+  EXPECT_TRUE(observer_->fired());
+}
+
+// The event should not fire if the preference is more recent than a day.
+TEST_F(DailyEventTest, TestRecentNotFired) {
+  base::Time last_time = base::Time::Now() - base::TimeDelta::FromMinutes(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  event_.CheckInterval();
+  EXPECT_FALSE(observer_->fired());
+}
+
+// The event should not fire if the preference is less than a day in the future.
+TEST_F(DailyEventTest, TestSoonNotFired) {
+  base::Time last_time = base::Time::Now() + base::TimeDelta::FromMinutes(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  event_.CheckInterval();
+  EXPECT_FALSE(observer_->fired());
+}
+
+}  // namespace metrics