[Sync] Add HasChildren() function and use it instead of GetFirstChildId()

chrome/browser/sync/syncable/syncable_unittest.cc

 // Copyright (c) 2011 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 "chrome/browser/sync/syncable/syncable.h"
 
 #include "build/build_config.h"
 
 #include <sys/types.h>
 
@@ skipping 189 matching lines @@
     WriteTransaction trans(FROM_HERE, UNITTEST, &dir);
     MutableEntry e(&trans, GET_BY_HANDLE, written_metahandle);
     e.Put(IS_DEL, true);
 
     EXPECT_EQ(0, CountEntriesWithName(&trans, trans.root_id(), name));
   }
 
   dir.SaveChanges();
 }
 
+TEST_F(SyncableGeneralTest, ChildrenOps) {
+  Directory dir;
+  dir.Open(db_path_, "SimpleTest", &delegate_);
+
+  int64 root_metahandle;
+  {
+    ReadTransaction rtrans(FROM_HERE, &dir);
+    Entry e(&rtrans, GET_BY_ID, rtrans.root_id());
+    ASSERT_TRUE(e.good());
+    root_metahandle = e.Get(META_HANDLE);
+  }
+
+  int64 written_metahandle;
+  const Id id = TestIdFactory::FromNumber(99);
+  std::string name = "Jeff";
+  {
+    ReadTransaction rtrans(FROM_HERE, &dir);
+    Entry e(&rtrans, GET_BY_ID, id);
+    ASSERT_FALSE(e.good());  // Hasn't been written yet.
+
+    EXPECT_FALSE(dir.HasChildren(&rtrans, rtrans.root_id()));
+    EXPECT_TRUE(dir.GetFirstChildId(&rtrans, rtrans.root_id()).IsRoot());
+  }
+
+  {
+    WriteTransaction wtrans(FROM_HERE, UNITTEST, &dir);
+    MutableEntry me(&wtrans, CREATE, wtrans.root_id(), name);
+    ASSERT_TRUE(me.good());
+    me.Put(ID, id);
+    me.Put(BASE_VERSION, 1);
+    written_metahandle = me.Get(META_HANDLE);
+  }
+
+  // Test children ops after something is now in the DB.
+  {
+    ReadTransaction rtrans(FROM_HERE, &dir);
+    Entry e(&rtrans, GET_BY_ID, id);
+    ASSERT_TRUE(e.good());
+
+    Entry child(&rtrans, GET_BY_HANDLE, written_metahandle);
+    ASSERT_TRUE(child.good());
+
+    EXPECT_TRUE(dir.HasChildren(&rtrans, rtrans.root_id()));
+    EXPECT_EQ(e.Get(ID), dir.GetFirstChildId(&rtrans, rtrans.root_id()));
+  }
+
+  {
+    WriteTransaction wtrans(FROM_HERE, UNITTEST, &dir);
+    MutableEntry me(&wtrans, GET_BY_HANDLE, written_metahandle);
+    ASSERT_TRUE(me.good());
+    me.Put(IS_DEL, true);
+  }
+
+  // Test children ops after the children have been deleted.
+  {
+    ReadTransaction rtrans(FROM_HERE, &dir);
+    Entry e(&rtrans, GET_BY_ID, id);
+    ASSERT_TRUE(e.good());
+
+    EXPECT_FALSE(dir.HasChildren(&rtrans, rtrans.root_id()));
+    EXPECT_TRUE(dir.GetFirstChildId(&rtrans, rtrans.root_id()).IsRoot());
+  }
+
+  dir.SaveChanges();
+}
+
 TEST_F(SyncableGeneralTest, ClientIndexRebuildsProperly) {
   int64 written_metahandle;
   TestIdFactory factory;
   const Id id = factory.NewServerId();
   std::string name = "cheesepuffs";
   std::string tag = "dietcoke";
 
   // Test creating a new meta entry.
   {
     Directory dir;
@@ skipping 1595 matching lines @@
 TEST_F(SyncableClientTagTest, TestClientTagIndexDuplicateServer) {
   EXPECT_TRUE(CreateWithDefaultTag(factory_.NewServerId(), true));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewServerId(), true));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewServerId(), false));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewLocalId(), false));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewLocalId(), true));
 }
 
 }  // namespace
 }  // namespace syncable