| // Copyright 2025 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/strings/lazy_string_builder.h" |
| |
| #include <string> |
| |
| #include "base/strings/string_number_conversions.h" |
| #include "testing/gtest/include/gtest/gtest.h" |
| |
| namespace base { |
| |
| TEST(LazyStringBuilderTest, Empty) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| EXPECT_EQ("", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendStringView) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| std::string_view sv = "hello"; |
| builder.AppendByReference(sv); |
| EXPECT_EQ("hello", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendCString) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference("hello"); |
| EXPECT_EQ("hello", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendLValueString) { |
| // The string must outlive the builder, and so be allocated first. |
| std::string lvalue_string = "lvalue"; |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference(lvalue_string); |
| EXPECT_EQ("lvalue", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendMultiple) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference("hello", " ", "world"); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendMultipleStringViews) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| std::string_view hello = "hello"; |
| std::string_view space = " "; |
| std::string_view world = "world"; |
| builder.AppendByReference(hello, space, world); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, AppendMultipleLValueStrings) { |
| std::string s1 = "hello"; |
| const std::string s2 = " "; |
| std::string s3 = "world"; |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference(s1, s2, s3); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| TEST(LazyStringBuilderTest, CopyAndAppend) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| std::string s = "world"; |
| builder.AppendByReference("hello "); |
| builder.AppendByValue(s); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, CopyAndAppendRvalue) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference("hello "); |
| builder.AppendByValue(std::string("world")); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, MixedAppend) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| std::string_view part1 = "The quick brown fox"; |
| std::string part2 = "jumps over"; |
| const char* part3 = "the lazy dog."; |
| |
| builder.AppendByReference(part1); |
| builder.AppendByReference(" "); |
| builder.AppendByValue(std::move(part2)); |
| builder.AppendByReference(" ", part3); |
| |
| EXPECT_EQ("The quick brown fox jumps over the lazy dog.", builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, ManyAppends) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| std::string expected; |
| for (int i = 0; i < 40; ++i) { |
| std::string s = base::NumberToString(i); |
| builder.AppendByValue(s); |
| |
| expected += s; |
| } |
| EXPECT_EQ(expected, builder.Build()); |
| } |
| |
| TEST(LazyStringBuilderTest, ManyAppendsVariadic) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", |
| "10", "11", "12", "13", "14", "15", "16", "17", |
| "18", "19", "20", "21", "22", "23", "24", "25", |
| "26", "27", "28", "29", "30", "31", "32", "33"); |
| EXPECT_EQ("0123456789101112131415161718192021222324252627282930313233", |
| builder.Build()); |
| } |
| |
| // Build() is a const method, so it can be called multiple times, and more |
| // things can be appended after calling it. |
| TEST(LazyStringBuilderTest, Reuse) { |
| auto builder = LazyStringBuilder::CreateForTesting(); |
| builder.AppendByReference("hello"); |
| EXPECT_EQ("hello", builder.Build()); |
| |
| builder.AppendByReference(" world"); |
| EXPECT_EQ("hello world", builder.Build()); |
| } |
| |
| } // namespace base |
