[Nav Experiment] Implement GetBackwardItems() and GetForwardItems().

Bug: 734150
Change-Id: I5198d481082fb5bc9e4a88b50847dcbebb97c248
Reviewed-on: https://chromium-review.googlesource.com/600292
Commit-Queue: Danyao Wang <danyao@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491876}

ios/web/navigation/navigation_manager_impl_unittest.mm

@@ -1827,6 +1827,136 @@ TEST_P(NavigationManagerTest, GetIndexOfItem) {
   EXPECT_EQ(-1, navigation_manager()->GetIndexOfItem(item_not_found.get()));
 }
 
+// Tests that GetBackwardItems() and GetForwardItems() return expected entries
+// when current item is in the middle of the navigation history.
+TEST_P(NavigationManagerTest, TestBackwardForwardItems) {
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/0"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_ setCurrentURL:@"http://www.url.com/0"];
+  navigation_manager()->CommitPendingItem();
+
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/1"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_ setCurrentURL:@"http://www.url.com/1"
+                  backListURLs:@[ @"http://www.url.com/0" ]
+               forwardListURLs:nil];
+  navigation_manager()->CommitPendingItem();
+
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/2"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_
+        setCurrentURL:@"http://www.url.com/2"
+         backListURLs:@[ @"http://www.url.com/0", @"http://www.url.com/1" ]
+      forwardListURLs:nil];
+  navigation_manager()->CommitPendingItem();
+
+  EXPECT_EQ(2, navigation_manager()->GetLastCommittedItemIndex());
+  NavigationItemList back_items = navigation_manager()->GetBackwardItems();
+  EXPECT_EQ(2U, back_items.size());
+  EXPECT_EQ("http://www.url.com/1", back_items[0]->GetURL().spec());
+  EXPECT_EQ("http://www.url.com/0", back_items[1]->GetURL().spec());
+  EXPECT_TRUE(navigation_manager()->GetForwardItems().empty());
+
+  if (GetParam() == TEST_WK_BASED_NAVIGATION_MANAGER) {
+    // TODO(crbug.com/734150): Enable this test once |GoToIndex| is
+    // implemented in WKBasedNavigationManager.
+    return;
+  }
+  navigation_manager()->GoBack();
+  EXPECT_EQ(1, navigation_manager()->GetLastCommittedItemIndex());
+  back_items = navigation_manager()->GetBackwardItems();
+  EXPECT_EQ(1U, back_items.size());
+  EXPECT_EQ("http://www.url.com/0", back_items[0]->GetURL().spec());
+  NavigationItemList forward_items = navigation_manager()->GetForwardItems();
+  EXPECT_EQ(1U, forward_items.size());
+  EXPECT_EQ("http://www.url.com/2", forward_items[0]->GetURL().spec());
+}
+
+// Tests that pending item is not considered part of session history so that
+// GetBackwardItems returns the second last committed item even if there is a
+// pendign item.
+TEST_P(NavigationManagerTest, NewPendingItemIsHiddenFromHistory) {
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/0"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_ setCurrentURL:@"http://www.url.com/0"];
+  navigation_manager()->CommitPendingItem();
+
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/1"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_ setCurrentURL:@"http://www.url.com/1"
+                  backListURLs:@[ @"http://www.url.com/0" ]
+               forwardListURLs:nil];
+  navigation_manager()->CommitPendingItem();
+
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/2"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  EXPECT_EQ(1, navigation_manager()->GetLastCommittedItemIndex());
+  EXPECT_TRUE(navigation_manager()->GetPendingItem());
+
+  NavigationItemList back_items = navigation_manager()->GetBackwardItems();
+  EXPECT_EQ(1U, back_items.size());
+  EXPECT_EQ("http://www.url.com/0", back_items[0]->GetURL().spec());
+}
+
+// Tests that all committed items are considered history if there is a transient
+// item. This can happen if an intersitial was loaded for SSL error.
+// See crbug.com/691311.
+TEST_P(NavigationManagerTest,
+       BackwardItemsShouldContainAllCommittedIfCurrentIsTransient) {
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/0"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+
+  [mock_wk_list_ setCurrentURL:@"http://www.url.com/0"];
+  navigation_manager()->CommitPendingItem();
+
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/1"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+  navigation_manager()->AddTransientItem(GURL("http://www.url.com/1"));
+
+  EXPECT_EQ(0, navigation_manager()->GetLastCommittedItemIndex());
+  EXPECT_TRUE(navigation_manager()->GetTransientItem());
+
+  NavigationItemList back_items = navigation_manager()->GetBackwardItems();
+  EXPECT_EQ(1U, back_items.size());
+  EXPECT_EQ("http://www.url.com/0", back_items[0]->GetURL().spec());
+}
+
+TEST_P(NavigationManagerTest, BackwardItemsShouldBeEmptyIfFirstIsTransient) {
+  navigation_manager()->AddPendingItem(
+      GURL("http://www.url.com/0"), Referrer(), ui::PAGE_TRANSITION_TYPED,
+      web::NavigationInitiationType::USER_INITIATED,
+      web::NavigationManager::UserAgentOverrideOption::INHERIT);
+  navigation_manager()->AddTransientItem(GURL("http://www.url.com/0"));
+
+  EXPECT_EQ(-1, navigation_manager()->GetLastCommittedItemIndex());
+  EXPECT_TRUE(navigation_manager()->GetTransientItem());
+
+  NavigationItemList back_items = navigation_manager()->GetBackwardItems();
+  EXPECT_TRUE(back_items.empty());
+}
+
 INSTANTIATE_TEST_CASE_P(
     ProgrammaticNavigationManagerTest,
     NavigationManagerTest,

ios/web/navigation/wk_based_navigation_manager_impl.mm

@@ -328,13 +328,29 @@ void WKBasedNavigationManagerImpl::GoToIndex(int index) {
 }
 
 NavigationItemList WKBasedNavigationManagerImpl::GetBackwardItems() const {
-  DLOG(WARNING) << "Not yet implemented.";
-  return NavigationItemList();
+  NavigationItemList items;
+
+  // If the current navigation item is a transient item (e.g. SSL
+  // interstitial), the last committed item should also be considered part of
+  // the backward history.
+  int wk_current_item_index = GetWKCurrentItemIndex();
+  if (GetTransientItem() && wk_current_item_index >= 0) {
+    items.push_back(GetItemAtIndex(wk_current_item_index));
+  }
+
+  for (int index = wk_current_item_index - 1; index >= 0; index--) {
+    items.push_back(GetItemAtIndex(index));
+  }
+  return items;
 }
 
 NavigationItemList WKBasedNavigationManagerImpl::GetForwardItems() const {
-  DLOG(WARNING) << "Not yet implemented.";
-  return NavigationItemList();
+  NavigationItemList items;
+  for (int index = GetWKCurrentItemIndex() + 1; index < GetItemCount();
+       index++) {
+    items.push_back(GetItemAtIndex(index));
+  }
+  return items;
 }
 
 void WKBasedNavigationManagerImpl::CopyStateFromAndPrune(

ios/web/navigation/wk_based_navigation_manager_impl_unittest.mm

@@ -78,10 +78,9 @@ TEST_F(WKBasedNavigationManagerTest, SyncAfterItemAtIndex) {
 
 // Tests that Referrer is inferred from the previous WKBackForwardListItem.
 TEST_F(WKBasedNavigationManagerTest, SyncAfterItemAtIndexWithPreviousItem) {
-  [mock_wk_list_
-        setCurrentURL:@"http://www.1.com"
-         backListURLs:[NSArray arrayWithObjects:@"http://www.0.com", nil]
-      forwardListURLs:[NSArray arrayWithObjects:@"http://www.2.com", nil]];
+  [mock_wk_list_ setCurrentURL:@"http://www.1.com"
+                  backListURLs:@[ @"http://www.0.com" ]
+               forwardListURLs:@[ @"http://www.2.com" ]];
   EXPECT_EQ(3, manager_->GetItemCount());
   EXPECT_EQ(1, manager_->GetLastCommittedItemIndex());
 
@@ -140,11 +139,9 @@ TEST_F(WKBasedNavigationManagerTest, GetItemAtIndexAfterCommitPending) {
   NavigationItem* pending_item2 = manager_->GetPendingItem();
 
   // Simulate an iframe navigation between the two main frame navigations.
-  [mock_wk_list_
-        setCurrentURL:@"http://www.2.com"
-         backListURLs:[NSArray arrayWithObjects:@"http://www.0.com",
-                                                @"http://www.1.com", nil]
-      forwardListURLs:nil];
+  [mock_wk_list_ setCurrentURL:@"http://www.2.com"
+                  backListURLs:@[ @"http://www.0.com", @"http://www.1.com" ]
+               forwardListURLs:nil];
   manager_->CommitPendingItem();
 
   EXPECT_EQ(3, manager_->GetItemCount());
@@ -172,10 +169,9 @@ TEST_F(WKBasedNavigationManagerTest, GetItemAtIndexAfterCommitPending) {
 // pending item is a back forward navigation.
 TEST_F(WKBasedNavigationManagerTest, ReusePendingItemForHistoryNavigation) {
   // Simulate two regular navigations.
-  [mock_wk_list_
-        setCurrentURL:@"http://www.1.com"
-         backListURLs:[NSArray arrayWithObjects:@"http://www.0.com", nil]
-      forwardListURLs:nil];
+  [mock_wk_list_ setCurrentURL:@"http://www.1.com"
+                  backListURLs:@[ @"http://www.0.com" ]
+               forwardListURLs:nil];
 
   // Force sync NavigationItems.
   NavigationItem* original_item0 = manager_->GetItemAtIndex(0);
@@ -188,7 +184,7 @@ TEST_F(WKBasedNavigationManagerTest, ReusePendingItemForHistoryNavigation) {
   WKBackForwardListItem* wk_item1 = [mock_wk_list_ itemAtIndex:0];
   mock_wk_list_.currentItem = wk_item0;
   mock_wk_list_.backList = nil;
-  mock_wk_list_.forwardList = [NSArray arrayWithObjects:wk_item1, nil];
+  mock_wk_list_.forwardList = @[ wk_item1 ];
   OCMExpect([mock_web_view_ URL])
       .andReturn([[NSURL alloc] initWithString:@"http://www.0.com"]);