GoogleTest做单元测试

环境准备

git clone https://github.com/google/googletest.git

说cmkae版本过低了，解决方法

进到googletest中

cmake CMakeLists.txt
make
sudo make install

ls /usr/local/lib

存在以下文件说明安装成功

中间出了个问题就是，总是出现链接不成功，导致库导入不进去

可以对G++命令加上-L编译的命令，这样就指定了库的搜索路径。

g++ sample1.cc sample1_unittest.cc -o sample1 -L/usr/local/lib -lgtest -lgtest_main -lpthread

GoogleTest

单元测试是用来对一个模块、一个函数或者一个类来进行正确性检测的测试工作。
比如我们测试一个岛问题的解决方法

#include <iostream>
#include <initializer_list>
#include <vector>
#include <gtest/gtest.h>using namespace std;class IslandProblem {
public:using Matrix = vector<vector<char>>;IslandProblem(const initializer_list<vector<char>> list) {_islands.assign(list);}int Do() {int num = 0;for (int row = 0; row < (int)_islands.size(); row++) {for (int col = 0; col < (int)_islands[row].size(); col++) {if (canUnion(row, col)) {num++;unionIsland(row, col);}}}return num;}protected:bool canUnion(int row, int col) {if (row < 0 || row >= (int)_islands.size())return false;if (col < 0 || col >= (int)_islands[row].size())return false;if (_islands[row][col] != 1)return false;return true;}void unionIsland(int row, int col) {_islands[row][col] = 2;// upif (canUnion(row-1, col)) unionIsland(row-1, col);// leftif (canUnion(row, col-1)) unionIsland(row, col-1);// downif (canUnion(row+1, col)) unionIsland(row+1, col);// rightif (canUnion(row, col+1)) unionIsland(row, col+1);}private:Matrix _islands;
};TEST(IslandProblem, logic) {IslandProblem ip1{{1,1,1,1},{1,0,1,1},{0,0,0,0},{1,0,1,0}};EXPECT_EQ(ip1.Do(), 3);IslandProblem ip2{{1,0,1,1},{1,0,1,1},{0,0,0,0},{1,0,1,0}};EXPECT_EQ(ip2.Do(), 4);
}TEST(IslandProblem, boundary) {IslandProblem ip1{{1,1,1,1},{1,0,0,1},{1,0,0,1},{1,1,1,1}};EXPECT_EQ(ip1.Do(), 1);IslandProblem ip2{};EXPECT_EQ(ip2.Do(), 0);
}TEST(IslandProblem, exception) {IslandProblem ip1{{-1,1,1,1},{1,0,0,1},{1,0,0,1},{1,1,1,1}};EXPECT_EQ(ip1.Do(), 1);
}

解决方法要考虑：逻辑问题（功能正确），边界问题，异常情况。TEST的测试案例中已经把这些问题考虑进去了。
然后实际去测试，说明解决方法能够考虑以上三种情况