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..39c46a4b553a40e309314d3f22f4f21bb212484b
--- /dev/null
+++ b/chrome/common/string_index_unittest.cc
@@ -0,0 +1,127 @@
+// 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, IsValid) {
+  StringIndex index_ = StringIndex("B");
+  EXPECT_TRUE(index_.IsValid());
+
+  index_ = StringIndex("AB");
+  EXPECT_TRUE(index_.IsValid());
+
+  index_ = StringIndex("AA");
+  EXPECT_FALSE(index_.IsValid());
+
+  index_ = StringIndex();
+  EXPECT_FALSE(index_.IsValid());
+}
+
+TEST(StringIndexTest, LessThan) {
+  StringIndex small = StringIndex("B");
+  StringIndex middle = StringIndex("N");
+  StringIndex big = StringIndex("Z");
+
+  EXPECT_TRUE(small.LessThan(middle));
+  EXPECT_TRUE(small.LessThan(big));
+  EXPECT_TRUE(middle.LessThan(big));
+
+  EXPECT_FALSE(big.LessThan(small));
+  EXPECT_FALSE(big.LessThan(middle));
+  EXPECT_FALSE(middle.LessThan(small));
+}
+
+TEST(StringIndexTest, CreateBetweenSingleDigit) {
+  StringIndex result = StringIndex("B").CreateBetween(StringIndex("D"));
+  EXPECT_EQ("C", result.ToString());
+
+  result = StringIndex("B").CreateBetween(StringIndex("E"));
+  EXPECT_EQ("C", result.ToString());
+
+  result = StringIndex("B").CreateBetween(StringIndex("F"));
+  EXPECT_EQ("D", result.ToString());
+
+  result = StringIndex("B").CreateBetween(StringIndex("C"));
+  EXPECT_EQ("BN", result.ToString());
+
+  result = StringIndex("C").CreateBetween(StringIndex("D"));
+  EXPECT_EQ("CN", result.ToString());
+}
+
+TEST(StringIndexTest, CreateBetweenDifferentLengths) {
+  StringIndex result = StringIndex("B").CreateBetween(StringIndex("BB"));
+  EXPECT_EQ("BAN", result.ToString());
+
+  result = StringIndex("BZ").CreateBetween(StringIndex("C"));
+  EXPECT_EQ("BZN", result.ToString());
+}
+
+TEST(StringIndexTest, CreateBetweenOverflow) {
+  StringIndex result = StringIndex("AB").CreateBetween(StringIndex("BB"));
+  EXPECT_EQ("AO", result.ToString());
+
+  result = StringIndex("BB").CreateBetween(StringIndex("CB"));
+  EXPECT_EQ("BO", result.ToString());
+
+  result = StringIndex("BBB").CreateBetween(StringIndex("BCB"));
+  EXPECT_EQ("BBO", result.ToString());
+
+  result = StringIndex("AAB").CreateBetween(StringIndex("ZZZ"));
+  EXPECT_EQ("N", result.ToString());
+
+  result = StringIndex("YYY").CreateBetween(StringIndex("ZZZ"));
+  EXPECT_EQ("ZML", result.ToString());
+
+  result = StringIndex("YAB").CreateBetween(StringIndex("ZZZ"));
+  EXPECT_EQ("Z", result.ToString());
+
+  result = StringIndex("AAZ").CreateBetween(StringIndex("ZZZ"));
+  EXPECT_EQ("NAM", result.ToString());
+}
+
+TEST(StringIndexTest, CreateAfter) {
+  StringIndex result = StringIndex("Y").CreateAfter();
+  EXPECT_EQ("YN", result.ToString());
+
+  result = StringIndex("ZY").CreateAfter();
+  EXPECT_EQ("ZYN", result.ToString());
+
+  result = StringIndex("ZZZY").CreateAfter();
+  EXPECT_EQ("ZZZYN", result.ToString());
+
+  result = StringIndex("YY").CreateAfter();
+  EXPECT_EQ("ZL", result.ToString());
+
+  result = StringIndex("YZ").CreateAfter();
+  EXPECT_EQ("ZM", result.ToString());
+
+  result = StringIndex("Z").CreateAfter();
+  EXPECT_EQ("ZM", result.ToString());
+}
+
+TEST(StringIndexTest, CreateBefore) {
+  StringIndex result = StringIndex("B").CreateBefore();
+  EXPECT_EQ("AN", result.ToString());
+
+  result = StringIndex("BB").CreateBefore();
+  EXPECT_EQ("AO", result.ToString());
+
+  result = StringIndex("BC").CreateBefore();
+  EXPECT_EQ("AO", result.ToString());
+
+  result = StringIndex("BD").CreateBefore();
+  EXPECT_EQ("AP", result.ToString());
+}
+
+TEST(StringIndexTest, ToString) {
+  StringIndex index = StringIndex("B");
+  EXPECT_EQ(index.ToString(), "B");
+
+  index = StringIndex("AAB");
+  EXPECT_EQ(index.ToString(), "AAB");
+
+  index = StringIndex("ZZZ");
+  EXPECT_EQ(index.ToString(), "ZZZ");
+}