[NTP Snippets] Don't reschedule background fetching on every startup

components/ntp_snippets/ntp_snippets_service_unittest.cc

 // Copyright 2015 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/ntp_snippets/ntp_snippets_service.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 464 matching lines @@
   base::ScopedTempDir database_dir_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsServiceTest);
 };
 
 TEST_F(NTPSnippetsServiceTest, ScheduleOnStart) {
   // We should get two |Schedule| calls: The first when initialization
   // completes, the second one after the automatic (since the service doesn't
   // have any data yet) fetch finishes.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
+  EXPECT_CALL(mock_scheduler(), Unschedule()).Times(0);
   auto service = MakeSnippetsService();
 
   // When we have no snippets are all, loading the service initiates a fetch.
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ("OK", service->snippets_fetcher()->last_status());
 }
 
+TEST_F(NTPSnippetsServiceTest, DontRescheduleOnStart) {
+  EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
+  EXPECT_CALL(mock_scheduler(), Unschedule()).Times(0);
+  auto service = MakeSnippetsService();
+  base::RunLoop().RunUntilIdle();
+
+  // When recreating the service, we should not get a single |Schedule| call:
+  // The tasks are already scheduled with the correct intervals, so nothing on
+  // initialization, but the service still has no data, so one |Schedule|
+  // happens after the automatic fetch.
+  Mock::VerifyAndClearExpectations(&mock_scheduler());
+  EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(1);
+  EXPECT_CALL(mock_scheduler(), Unschedule()).Times(0);
+  ResetSnippetsService(&service);
+  base::RunLoop().RunUntilIdle();
+}
+
 TEST_F(NTPSnippetsServiceTest, RescheduleAfterSuccessfulFetch) {
   // We should get two |Schedule| calls: The first when initialization
   // completes, the second one after the automatic (since the service doesn't
   // have any data yet) fetch finishes.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
   auto service = MakeSnippetsService();
   base::RunLoop().RunUntilIdle();
 
   // A successful fetch should trigger another |Schedule|.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _));
   LoadFromJSONString(service.get(), GetTestJson({GetSnippet()}));
 }
 
 TEST_F(NTPSnippetsServiceTest, DontRescheduleAfterFailedFetch) {
   // We should get two |Schedule| calls: The first when initialization
   // completes, the second one after the automatic (since the service doesn't
   // have any data yet) fetch finishes.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
   auto service = MakeSnippetsService();
   base::RunLoop().RunUntilIdle();
 
   // A failed fetch should NOT trigger another |Schedule|.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(0);
   LoadFromJSONString(service.get(), GetTestJson({GetInvalidSnippet()}));
 }
 
-TEST_F(NTPSnippetsServiceTest, DontRescheduleBeforeInit) {
+TEST_F(NTPSnippetsServiceTest, IgnoreRescheduleBeforeInit) {
   // We should get two |Schedule| calls: The first when initialization
   // completes, the second one after the automatic (since the service doesn't
   // have any data yet) fetch finishes.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
   // The |RescheduleFetching| call shouldn't do anything (in particular not
   // result in an |Unschedule|), since the service isn't initialized yet.
   EXPECT_CALL(mock_scheduler(), Unschedule()).Times(0);
   auto service = MakeSnippetsServiceWithoutInitialization();
-  service->RescheduleFetching();
+  service->RescheduleFetching(false);
   WaitForSnippetsServiceInitialization();
+}
 
-  // Now that initialization has finished, |RescheduleFetching| should work.
-  EXPECT_CALL(mock_scheduler(), Schedule(_, _));
-  service->RescheduleFetching();
+TEST_F(NTPSnippetsServiceTest, HandleForcedRescheduleBeforeInit) {
+  {
+    InSequence s;
+    // The |RescheduleFetching| call with force=true should result in an
+    // |Unschedule|, since the service isn't initialized yet.
+    EXPECT_CALL(mock_scheduler(), Unschedule()).Times(1);
+    // We should get two |Schedule| calls: The first when initialization
+    // completes, the second one after the automatic (since the service doesn't
+    // have any data yet) fetch finishes.
+    EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
+  }
+  auto service = MakeSnippetsServiceWithoutInitialization();
+  service->RescheduleFetching(true);
+  WaitForSnippetsServiceInitialization();
 }
 
 TEST_F(NTPSnippetsServiceTest, RescheduleOnStateChange) {
   {
     InSequence s;
     // Initial startup.
     EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
     // Service gets disabled.
     EXPECT_CALL(mock_scheduler(), Unschedule());
     // Service gets enabled again.
     EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
   }
   auto service = MakeSnippetsService();
   ASSERT_TRUE(service->ready());
   base::RunLoop().RunUntilIdle();
 
   service->OnDisabledReasonChanged(DisabledReason::EXPLICITLY_DISABLED);
   ASSERT_FALSE(service->ready());
   base::RunLoop().RunUntilIdle();
 
   service->OnDisabledReasonChanged(DisabledReason::NONE);
   ASSERT_TRUE(service->ready());
   base::RunLoop().RunUntilIdle();
 }
 
+TEST_F(NTPSnippetsServiceTest, DontUnscheduleOnShutdown) {
+  EXPECT_CALL(mock_scheduler(), Schedule(_, _)).Times(2);
+  EXPECT_CALL(mock_scheduler(), Unschedule()).Times(0);
+
+  auto service = MakeSnippetsService();
+  base::RunLoop().RunUntilIdle();
+
+  service.reset();
+  base::RunLoop().RunUntilIdle();
+}
+
 TEST_F(NTPSnippetsServiceTest, Full) {
   std::string json_str(GetTestJson({GetSnippet()}));
 
   auto service = MakeSnippetsService();
 
   LoadFromJSONString(service.get(), json_str);
 
   ASSERT_THAT(observer().SuggestionsForCategory(articles_category()),
               SizeIs(1));
   ASSERT_THAT(service->GetSnippetsForTesting(articles_category()), SizeIs(1));
@@ skipping 469 matching lines @@
              end = base::Time::FromTimeT(456);
   base::Callback<bool(const GURL& url)> filter;
   service->ClearHistory(begin, end, filter);
 
   EXPECT_THAT(service->GetSnippetsForTesting(articles_category()), IsEmpty());
   EXPECT_THAT(service->GetDismissedSnippetsForTesting(articles_category()),
               IsEmpty());
 }
 
 }  // namespace ntp_snippets