Create StringOrdinal to allow placement of strings in sorted lists

chrome/common/string_index_unittest.cc

Index: chrome/common/string_index_unittest.cc
diff --git a/chrome/common/string_index_unittest.cc b/chrome/common/string_index_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ff955005c81141a0c87a6bddc2466276de0b780f
--- /dev/null
+++ b/chrome/common/string_index_unittest.cc
@@ -0,0 +1,37 @@
+// 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/common/string_index.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(StringIndexTest, CreateStringBetweenSingleDigit) {
+  EXPECT_EQ("C", StringIndex::CreateStringBetween("B", "D"));
+  EXPECT_EQ("C", StringIndex::CreateStringBetween("B", "E"));
+  EXPECT_EQ("D", StringIndex::CreateStringBetween("B", "F"));
+
+  EXPECT_EQ("BN", StringIndex::CreateStringBetween("B","C"));
+  EXPECT_EQ("CN", StringIndex::CreateStringBetween("C","D"));
+}
+
+TEST(StringIndexTest, CreateStringBetweenEnd) {
+  EXPECT_EQ("YN", StringIndex::CreateStringBetween("Y", ""));
+  EXPECT_EQ("ZYN", StringIndex::CreateStringBetween("ZY", ""));
+  EXPECT_EQ("ZZZYN", StringIndex::CreateStringBetween("ZZZY",""));
+  EXPECT_EQ("ZL", StringIndex::CreateStringBetween("YY",""));
+  EXPECT_EQ("ZM", StringIndex::CreateStringBetween("YZ",""));
+  EXPECT_EQ("ZM", StringIndex::CreateStringBetween("Z",""));
+}
+
+TEST(StringIndexTest, CreateStringBetweenStart) {
+  EXPECT_EQ("AN", StringIndex::CreateStringBetween("", "B"));
+  EXPECT_EQ("AN", StringIndex::CreateStringBetween("", "BB"));
+  EXPECT_EQ("AO", StringIndex::CreateStringBetween("", "BC"));
+  EXPECT_EQ("AO", StringIndex::CreateStringBetween("", "BD"));
+}
+
+TEST(StringIndexTest, CreateStringBetweenLastDigitTheSame) {
+  EXPECT_EQ("AO", StringIndex::CreateStringBetween("AB", "BB"));
+  EXPECT_EQ("BO", StringIndex::CreateStringBetween("BB", "CB"));
+  EXPECT_EQ("BBO", StringIndex::CreateStringBetween("BBB", "BCB"));
+}