Create StringOrdinal to allow placement of strings in sorted lists

chrome/common/string_ordinal_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/common/string_ordinal.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+TEST(StringOrdinalTest, IsValid) {
+  EXPECT_TRUE(StringOrdinal("b").IsValid());
+  EXPECT_TRUE(StringOrdinal("ab").IsValid());
+
+  EXPECT_FALSE(StringOrdinal("aa").IsValid());
+  EXPECT_FALSE(StringOrdinal().IsValid());
+}
+
+TEST(StringOrdinalTest, LessThan) {
+  StringOrdinal small("b");
+  StringOrdinal middle("n");
+  StringOrdinal big("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));
+}
+
+// Tests the CreateBetween StringOrdinal function by calling
+// on the small_value with the large_value as the  parameter and
+// vice-versa.
+void TestCreateBetween(StringOrdinal small_value,
+                       StringOrdinal large_value,
+                       const std::string& expected_result) {
+  StringOrdinal result = small_value.CreateBetween(large_value);
+  EXPECT_EQ(expected_result, result.ToString());
+
+  result = large_value.CreateBetween(small_value);
+  EXPECT_EQ(expected_result, result.ToString());
+}
+
+TEST(StringOrdinalTest, CreateBetweenSingleDigit) {
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("d"), "c");
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("e"), "c");
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("f"), "d");
+  TestCreateBetween(StringOrdinal("c"), StringOrdinal("d"), "cn");
+}
+
+TEST(StringOrdinalTest, CreateBetweenDifferentLengths) {
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("bb"), "ban");
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("db"), "c");
+  TestCreateBetween(StringOrdinal("bz"), StringOrdinal("c"), "bzn");
+  TestCreateBetween(StringOrdinal("baaaaaab"), StringOrdinal("d"), "c");
+  TestCreateBetween(StringOrdinal("baaaaaac"), StringOrdinal("d"), "c");
+  TestCreateBetween(StringOrdinal("b"), StringOrdinal("daaaaaaab"), "c");
+}
+
+TEST(StringOrdinalTest, CreateBetweenOverflow) {
+  TestCreateBetween(StringOrdinal("ab"), StringOrdinal("bb"), "ao");
+  TestCreateBetween(StringOrdinal("bb"), StringOrdinal("cb"), "bo");
+  TestCreateBetween(StringOrdinal("bbb"), StringOrdinal("bcb"), "bbo");
+  TestCreateBetween(StringOrdinal("aab"), StringOrdinal("zzz"), "n");
+  TestCreateBetween(StringOrdinal("yyy"), StringOrdinal("zzz"), "zml");
+  TestCreateBetween(StringOrdinal("yab"), StringOrdinal("zzz"), "z");
+  TestCreateBetween(StringOrdinal("aaz"), StringOrdinal("zzz"), "n");
+  TestCreateBetween(StringOrdinal("nnnnz"), StringOrdinal("mmmmz"), "n");
+}
+
+TEST(StringOrdinalTest, CreateAfter) {
+  StringOrdinal result = StringOrdinal("y").CreateAfter();
+  EXPECT_EQ("yn", result.ToString());
+
+  result = StringOrdinal("zy").CreateAfter();
+  EXPECT_EQ("zyn", result.ToString());
+
+  result = StringOrdinal("zzzy").CreateAfter();
+  EXPECT_EQ("zzzyn", result.ToString());
+
+  result = StringOrdinal("yy").CreateAfter();
+  EXPECT_EQ("zl", result.ToString());
+
+  result = StringOrdinal("yz").CreateAfter();
+  EXPECT_EQ("z", result.ToString());
+
+  result = StringOrdinal("z").CreateAfter();
+  EXPECT_EQ("zm", result.ToString());
+}
+
+TEST(StringOrdinalTest, CreateBefore) {
+  StringOrdinal result = StringOrdinal("b").CreateBefore();
+  EXPECT_EQ("an", result.ToString());
+
+  result = StringOrdinal("bb").CreateBefore();
+  EXPECT_EQ("ao", result.ToString());
+
+  result = StringOrdinal("bc").CreateBefore();
+  EXPECT_EQ("ao", result.ToString());
+
+  result = StringOrdinal("bd").CreateBefore();
+  EXPECT_EQ("ap", result.ToString());
+}
+
+TEST(StringOrdinalTest, ToString) {
+  StringOrdinal index("b");
+  EXPECT_EQ(index.ToString(), "b");
+
+  index = StringOrdinal("aab");
+  EXPECT_EQ(index.ToString(), "aab");
+
+  index = StringOrdinal("zzz");
+  EXPECT_EQ(index.ToString(), "zzz");
+}
+}  // namespace