[NTP::RecentTabs] Do not fetch all pages when not a recent tab is added.

components/ntp_snippets/offline_pages/recent_tab_suggestions_provider_unittest.cc

 // Copyright 2016 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/offline_pages/recent_tab_suggestions_provider.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 164 matching lines @@
 TEST_F(RecentTabSuggestionsProviderTest, ShouldDeliverCorrectCategoryInfo) {
   EXPECT_FALSE(
       provider()->GetCategoryInfo(recent_tabs_category()).has_more_action());
   EXPECT_FALSE(
       provider()->GetCategoryInfo(recent_tabs_category()).has_reload_action());
   EXPECT_FALSE(provider()
                    ->GetCategoryInfo(recent_tabs_category())
                    .has_view_all_action());
 }
 
+// TODO(vitaliii): Break this test into multiple tests. Currently if it fails,
+// it takes long time to find which part of it actually fails.
 TEST_F(RecentTabSuggestionsProviderTest, ShouldDismiss) {
-  EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _)).Times(4);
-  auto recent_tabs_list = CreateDummyRecentTabs({1, 2, 3, 4});
-  for (OfflinePageItem& recent_tab : recent_tabs_list)
+  EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _)).Times(3);
+  auto recent_tabs_list = CreateDummyRecentTabs({1, 2, 3});
+  for (OfflinePageItem& recent_tab : recent_tabs_list) {
     AddOfflinePageToModel(recent_tab);
+  }
 
   // Dismiss 2 and 3.
   EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _)).Times(0);
   provider()->DismissSuggestion(GetDummySuggestionId(2));
   provider()->DismissSuggestion(GetDummySuggestionId(3));
   Mock::VerifyAndClearExpectations(observer());
 
   // They should disappear from the reported suggestions.
   EXPECT_CALL(
       *observer(),
-      OnNewSuggestions(_, recent_tabs_category(),
-                       UnorderedElementsAre(
-                           Property(&ContentSuggestion::url,
-                                    GURL("http://dummy.com/1")),
-                           Property(&ContentSuggestion::url,
-                                    GURL("http://dummy.com/4")))));
+      OnNewSuggestions(
+          _, recent_tabs_category(),
+          UnorderedElementsAre(
+              Property(&ContentSuggestion::url, GURL("http://dummy.com/1")),
+              Property(&ContentSuggestion::url, GURL("http://dummy.com/4")))));
 
-  AddOfflinePageToModel(ntp_snippets::test::CreateDummyOfflinePageItem(
-      4, offline_pages::kDefaultNamespace));
+  AddOfflinePageToModel(CreateDummyRecentTab(4));
   Mock::VerifyAndClearExpectations(observer());
 
   // And appear in the dismissed suggestions.
   std::vector<ContentSuggestion> dismissed_suggestions;
   provider()->GetDismissedSuggestionsForDebugging(
       recent_tabs_category(),
       base::Bind(&CaptureDismissedSuggestions, &dismissed_suggestions));
   EXPECT_THAT(
       dismissed_suggestions,
       UnorderedElementsAre(Property(&ContentSuggestion::url,
                                     GURL("http://dummy.com/2")),
                            Property(&ContentSuggestion::url,
                                     GURL("http://dummy.com/3"))));
 
   // Clear dismissed suggestions.
   provider()->ClearDismissedSuggestionsForDebugging(recent_tabs_category());
 
   // They should be gone from the dismissed suggestions.
   dismissed_suggestions.clear();
   provider()->GetDismissedSuggestionsForDebugging(
       recent_tabs_category(),
       base::Bind(&CaptureDismissedSuggestions, &dismissed_suggestions));
   EXPECT_THAT(dismissed_suggestions, IsEmpty());
 
   // And appear in the reported suggestions for the category again.
   EXPECT_CALL(*observer(),
-              OnNewSuggestions(_, recent_tabs_category(), SizeIs(4)));
-  AddOfflinePageToModel(ntp_snippets::test::CreateDummyOfflinePageItem(
-      5, offline_pages::kDefaultNamespace));
+              OnNewSuggestions(_, recent_tabs_category(), SizeIs(5)));
+  AddOfflinePageToModel(CreateDummyRecentTab(5));
   Mock::VerifyAndClearExpectations(observer());
 }
 
 TEST_F(RecentTabSuggestionsProviderTest,
        ShouldInvalidateWhenOfflinePageDeleted) {
   EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _)).Times(3);
   std::vector<OfflinePageItem> offline_pages = CreateDummyRecentTabs({1, 2, 3});
   for (OfflinePageItem& recent_tab : offline_pages)
     AddOfflinePageToModel(recent_tab);
 
@@ skipping 51 matching lines @@
   EXPECT_CALL(*observer(),
               OnNewSuggestions(
                   _, recent_tabs_category(),
                   UnorderedElementsAre(
                       Property(&ContentSuggestion::publish_date, now),
                       Property(&ContentSuggestion::publish_date, tomorrow))));
 
   AddOfflinePageToModel(offline_pages[2]);
 }
 
+TEST_F(RecentTabSuggestionsProviderTest,
+       ShouldNotFetchIfAddedOfflinePageIsNotRecentTab) {
+  // The provider is not notified about the first recent tab yet.
+  model()->mutable_items()->push_back(CreateDummyRecentTab(1));
+  // It should not fetch when not a recent tab is added, thus, it should not
+  // report the first recent tab (which it is not aware about).
+  EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _)).Times(0);
+  AddOfflinePageToModel(ntp_snippets::test::CreateDummyOfflinePageItem(
+      2, offline_pages::kDefaultNamespace));
+}
+
+TEST_F(RecentTabSuggestionsProviderTest,
+       ShouldFetchIfAddedOfflinePageIsRecentTab) {
+  // The provider is not notified about the first recent tab yet.
+  model()->mutable_items()->push_back(CreateDummyRecentTab(1));
+  // However, it must return the first recent tab (i.e. manually fetch it) even
+  // when notified about a different recent tab.
+  EXPECT_CALL(
+      *observer(),
+      OnNewSuggestions(
+          _, recent_tabs_category(),
+          UnorderedElementsAre(
+              Property(&ContentSuggestion::url, GURL("http://dummy.com/1")),
+              Property(&ContentSuggestion::url, GURL("http://dummy.com/2")))));
+  AddOfflinePageToModel(CreateDummyRecentTab(2));
+}
+
 }  // namespace ntp_snippets