Handle correctly start and commit of non-latest navigations.

ios/web/navigation/crw_session_controller_unittest.mm

 // Copyright 2012 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.
 
 #import "ios/web/navigation/crw_session_controller.h"
 
 #import <Foundation/Foundation.h>
 
 #include <utility>
 
@@ skipping 354 matching lines @@
   [session_controller_ commitPendingItem];
   [session_controller_
                addPendingItem:GURL("http://www.example.com/2")
                      referrer:MakeReferrer("http://www.example.com/c")
                    transition:ui::PAGE_TRANSITION_LINK
                initiationType:web::NavigationInitiationType::RENDERER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
 
   // Go back to the first item.
-  [session_controller_ goToItemAtIndex:0];
+  [session_controller_ goToItemAtIndex:0 discardNonCommittedItems:NO];
 
   // Create and commit a new pending item.
   [session_controller_
                addPendingItem:GURL("http://www.example.com/2")
                      referrer:MakeReferrer("http://www.example.com/c")
                    transition:ui::PAGE_TRANSITION_LINK
                initiationType:web::NavigationInitiationType::RENDERER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
 
@@ skipping 23 matching lines @@
   [session_controller_
                addPendingItem:GURL("http://www.example.com/2")
                      referrer:web::Referrer()
                    transition:ui::PAGE_TRANSITION_TYPED
                initiationType:web::NavigationInitiationType::USER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
   ASSERT_EQ(3U, [session_controller_ items].size());
 
   // Go to the middle, and commit first pending item index.
-  [session_controller_ goToItemAtIndex:1];
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:NO];
   [session_controller_ setPendingItemIndex:0];
   ASSERT_EQ(0, [session_controller_ pendingItemIndex]);
   web::NavigationItem* pending_item = [session_controller_ pendingItem];
   ASSERT_TRUE(pending_item);
   ASSERT_EQ(1, [session_controller_ lastCommittedItemIndex]);
   EXPECT_EQ(2, [session_controller_ previousItemIndex]);
   [session_controller_ commitPendingItem];
 
   // Verify that pending item has been committed and current and previous item
   // indices updated.
@@ skipping 387 matching lines @@
   [session_controller_
                addPendingItem:GURL("http://www.url2.com")
                      referrer:MakeReferrer("http://www.referer.com")
                    transition:ui::PAGE_TRANSITION_TYPED
                initiationType:web::NavigationInitiationType::USER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
 
   EXPECT_EQ(session_controller_.get().previousItemIndex, 1);
 
-  [session_controller_ goToItemAtIndex:1];
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:NO];
   EXPECT_EQ(session_controller_.get().previousItemIndex, 2);
 
-  [session_controller_ goToItemAtIndex:0];
+  [session_controller_ goToItemAtIndex:0 discardNonCommittedItems:NO];
   EXPECT_EQ(session_controller_.get().previousItemIndex, 1);
 
-  [session_controller_ goToItemAtIndex:1];
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:NO];
   EXPECT_EQ(session_controller_.get().previousItemIndex, 0);
 
-  [session_controller_ goToItemAtIndex:2];
+  [session_controller_ goToItemAtIndex:2 discardNonCommittedItems:NO];
   EXPECT_EQ(session_controller_.get().previousItemIndex, 1);
 }
 
 TEST_F(CRWSessionControllerTest, PushNewItem) {
   std::vector<std::unique_ptr<web::NavigationItem>> items;
   items.push_back(CreateNavigationItem("http://www.firstpage.com",
                                        "http://www.starturl.com", @"First"));
   items.push_back(CreateNavigationItem("http://www.secondpage.com",
                                        "http://www.firstpage.com", @"Second"));
   items.push_back(CreateNavigationItem("http://www.thirdpage.com",
@@ skipping 145 matching lines @@
                initiationType:web::NavigationInitiationType::USER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
 
   EXPECT_EQ(3, session_controller_.get().lastCommittedItemIndex);
   web::NavigationItemList backItems = [session_controller_ backwardItems];
   EXPECT_EQ(2U, backItems.size());
   EXPECT_TRUE([session_controller_ forwardItems].empty());
   EXPECT_EQ("http://www.example.com/redirect", backItems[0]->GetURL().spec());
 
-  [session_controller_ goToItemAtIndex:1];
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:NO];
   EXPECT_EQ(1U, [session_controller_ backwardItems].size());
   EXPECT_EQ(1U, [session_controller_ forwardItems].size());
 
-  [session_controller_ goToItemAtIndex:0];
+  [session_controller_ goToItemAtIndex:0 discardNonCommittedItems:NO];
   web::NavigationItemList forwardItems = [session_controller_ forwardItems];
   EXPECT_EQ(0U, [session_controller_ backwardItems].size());
   EXPECT_EQ(2U, forwardItems.size());
   EXPECT_EQ("http://www.example.com/2", forwardItems[1]->GetURL().spec());
 }
 
 // Tests going to items with existing and non-existing indices.
 TEST_F(CRWSessionControllerTest, GoToItemAtIndex) {
   [session_controller_
                addPendingItem:GURL("http://www.example.com/0")
@@ skipping 28 matching lines @@
                      referrer:MakeReferrer("http://www.example.com/d")
                    transition:ui::PAGE_TRANSITION_LINK
                initiationType:web::NavigationInitiationType::USER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ addTransientItemWithURL:GURL("http://www.example.com")];
   EXPECT_EQ(3, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(2, session_controller_.get().previousItemIndex);
   EXPECT_TRUE([session_controller_ pendingItem]);
   EXPECT_TRUE([session_controller_ transientItem]);
 
+  // Going back and forth without discaring transient and pending items.
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:NO];
+  EXPECT_EQ(1, session_controller_.get().lastCommittedItemIndex);
+  EXPECT_EQ(3, session_controller_.get().previousItemIndex);
+  EXPECT_TRUE(session_controller_.get().pendingItem);
+  EXPECT_TRUE(session_controller_.get().transientItem);
+  [session_controller_ goToItemAtIndex:3 discardNonCommittedItems:NO];
+  EXPECT_EQ(3, session_controller_.get().lastCommittedItemIndex);
+  EXPECT_EQ(1, session_controller_.get().previousItemIndex);
+  EXPECT_TRUE(session_controller_.get().pendingItem);
+  EXPECT_TRUE(session_controller_.get().transientItem);
+
   // Going back should discard transient and pending items.
-  [session_controller_ goToItemAtIndex:1];
+  [session_controller_ goToItemAtIndex:1 discardNonCommittedItems:YES];
   EXPECT_EQ(1, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(3, session_controller_.get().previousItemIndex);
   EXPECT_FALSE(session_controller_.get().pendingItem);
   EXPECT_FALSE(session_controller_.get().transientItem);
 
   // Going forward should discard transient item.
   [session_controller_ addTransientItemWithURL:GURL("http://www.example.com")];
   EXPECT_TRUE(session_controller_.get().transientItem);
-  [session_controller_ goToItemAtIndex:2];
+  [session_controller_ goToItemAtIndex:2 discardNonCommittedItems:YES];
   EXPECT_EQ(2, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(1, session_controller_.get().previousItemIndex);
   EXPECT_FALSE(session_controller_.get().transientItem);
 
   // Out of bounds navigations should be no-op.
-  [session_controller_ goToItemAtIndex:-1];
+  [session_controller_ goToItemAtIndex:-1 discardNonCommittedItems:NO];
   EXPECT_EQ(2, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(1, session_controller_.get().previousItemIndex);
-  [session_controller_ goToItemAtIndex:NSIntegerMax];
+  [session_controller_ goToItemAtIndex:NSIntegerMax
+              discardNonCommittedItems:NO];
   EXPECT_EQ(2, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(1, session_controller_.get().previousItemIndex);
 
   // Going to current index should not change the previous index.
-  [session_controller_ goToItemAtIndex:2];
+  [session_controller_ goToItemAtIndex:2 discardNonCommittedItems:NO];
   EXPECT_EQ(2, session_controller_.get().lastCommittedItemIndex);
   EXPECT_EQ(1, session_controller_.get().previousItemIndex);
 }
 
 // Tests that visible URL is the same as transient URL if there are no committed
 // items.
 TEST_F(CRWSessionControllerTest, VisibleItemWithSingleTransientItem) {
   [session_controller_ addTransientItemWithURL:GURL("http://www.example.com")];
   web::NavigationItem* visible_item = [session_controller_ visibleItem];
   ASSERT_TRUE(visible_item);
@@ skipping 127 matching lines @@
                addPendingItem:GURL("http://www.example.com/0")
                      referrer:MakeReferrer("http://www.example.com/b")
                    transition:ui::PAGE_TRANSITION_CLIENT_REDIRECT
                initiationType:web::NavigationInitiationType::RENDERER_INITIATED
       userAgentOverrideOption:UserAgentOverrideOption::INHERIT];
   [session_controller_ commitPendingItem];
   EXPECT_EQ(0U, [session_controller_ backwardItems].size());
 }
 
 }  // anonymous namespace