Mac下GTest的基本使用
gtest全称Google C++ Testing Framework，它是从谷歌内部诞生并受到业界追捧的一个非常优秀的测试框架，支持如自动发现测试、自定义断言、死亡测试、自动报告等诸多功能。
本文记录Mac下安装配置gtest以及它的基本应用
一、安装
博主尝试用brew install 遇到了问题，于是直接源码安装
编译安装
git clone https://github.com/google/googletest
cd googletest
mkdir build && cd build
cmake ..
make
make install
测试代码
CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
set(CMAKE_CXX_STANDARD 11)
project(demo)
find_package(GTEST REQUIRED)
add_executable(${PROJECT_NAME} main.cpp)
target_link_libraries(${PROJECT_NAME} ${GTEST_LIBRARIES})
main.cpp
#include <iostream>
#include <gtest/gtest.h>
int add(int a, int b) {
return a + b;
}
int sub(int a, int b) {
return a - b;
}
// case1
TEST(test, c1) {
EXPECT_EQ(3, add(1, 2));
EXPECT_EQ(12, add(2, 6));
}
// case2
TEST(test, c2) {
EXPECT_EQ(-1, sub(1, 2));
}
GTEST_API_ int main(int argc, char ** argv) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
编译运行
cmake .
make
./demo
# 输出
➜ build ./demo
[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from test
[ RUN ] test.c1
/Users/fanghao/Desktop/test/main.cpp:15: Failure
Expected equality of these values:
12
add(2, 6)
Which is: 8
[ FAILED ] test.c1 (0 ms)
[ RUN ] test.c2
[ OK ] test.c2 (0 ms)
[----------] 2 tests from test (0 ms total)
[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (0 ms total)
[ PASSED ] 1 test.
[ FAILED ] 1 test, listed below:
[ FAILED ] test.c1
1 FAILED TEST
二、基本概念
-
断言：即assertion，检查条件是否为真，一个断言的结果有
- sucess
- nonfatal failure（非致命失败）
- fatal failure（致命失败）
这里值得注意的是后两个，nonfatal failure会指出错误，然后继续运行，由EXPECT_XX产生，fatal failure会指出错误但是终止当前测试函数，由ASSERT_XX产生，一般推荐用前者，这样一次可以查出多个问题
-
测试样例：test case表示要测试的对象，一般TEST会有两个参数，分别是测试样例，以及测试的子case，如下面这个测试阶乘的样例，HandlesZeroInput和HandlesPositiveInput都属于FactorialTest这个测试样例
// Tests factorial of 0 TEST(FactorialTest, HandlesZeroInput) { EXPECT_EQ(1, Factorial(0)); } // Tests factorial of positive numbers. TEST(FactorialTest, HandlesPositiveInput) { EXPECT_EQ(1, Factorial(1)); EXPECT_EQ(2, Factorial(2)); EXPECT_EQ(6, Factorial(3)); EXPECT_EQ(40320, Factorial(8)); } -
常用断言
Fatal assertion Nonfatal assertion Verifies ASSERT_TRUE(condition); EXPECT_TRUE(condition); condition is true ASSERT_FALSE(condition); EXPECT_FALSE(condition); condition is false ASSERT_EQ(expected, actual); EXPECT_EQ(expected, actual); expected == actual ASSERT_NE(val1, val2); EXPECT_NE(val1, val2); val1 != val2 ASSERT_LT(val1, val2); EXPECT_LT(val1, val2); val1 < val2 ASSERT_LE(val1, val2); EXPECT_LE(val1, val2); val1 <= val2 ASSERT_GT(val1, val2); EXPECT_GT(val1, val2); val1 > val2 ASSERT_GE(val1, val2); EXPECT_GE(val1, val2); val1 >= val2 ASSERT_STREQ(expected_str, actual_str); EXPECT_STREQ(expected_str, actual_str); the two C strings have the same content ASSERT_STRNE(str1, str2); EXPECT_STRNE(str1,str2); the two C strings have different content ASSERT_STRCASEEQ(expected_str, actual_str); EXPECT_STRCASEEQ(expected_str, actual_str); the two C strings have the same content,ignore case ASSERT_STRCASENE(str1, str2); EXPECT_STRCASENE(str1,str2); the two C strings have different content,ignore case
三、 Test Fixture
Test Fixture是对基本test case的封装，如果多个test需要操作类似数据，可以把他们封装在一个类里面，然后共享一些配置。
编写Fixure步骤
- 建立一个类，并继承::testing::Test，并且使用protected或public限制符，以便其子类可以访问到共享的数据
- 在这个类中，声明你想复用的对象。
- 写一个SetUp函数来准备所需对象
- 写一个TearDown函数来释放资源
- 其他用法和基本的test case一样，只是用TEST_F()宏代替TEST()宏，每次调用一个TEST_F都会重新运行一次SetUp和TearDown，但但成员对象可以共享
看一个示例应该更能说明问题
#include <iostream>
#include <gtest/gtest.h>
class Foo
{
public:
int add(int a, int b)
{
return a + b;
}
int sub(int a, int b)
{
return a - b;
}
};
class FooTest : public ::testing::Test
{
protected:
Foo foo; // shared object
// SetUp && TearDown will be called for every Test Case
virtual void SetUp()
{
std::cout << "Code here will be called immediately after the constructor" << std::endl;
}
virtual void TearDown()
{
std::cout << "Code here will be called immediately after each test" << std::endl;
}
};
// Test Case 1
TEST_F(FooTest, TestMethodAdd)
{
EXPECT_EQ(3, foo.add(1, 2));
}
// Test Case 2
TEST_F(FooTest, TestMethodSub)
{
EXPECT_EQ(-1, foo.sub(1, 2));
}
int main(int argc, char *argv[])
{
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
# 输出
➜ build ./demo
[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from FooTest
[ RUN ] FooTest.TestMethodAdd
Code here will be called immediately after the constructor
Code here will be called immediately after each test
[ OK ] FooTest.TestMethodAdd (0 ms)
[ RUN ] FooTest.TestMethodSub
Code here will be called immediately after the constructor
Code here will be called immediately after each test
[ OK ] FooTest.TestMethodSub (0 ms)
[----------] 2 tests from FooTest (0 ms total)
[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (1 ms total)
[ PASSED ] 2 tests.
四、小结
感觉gtest还是挺优雅的，适合TDD模式，把测试和开发完全解耦。