C++框架如何利用测试驱动开发提高可维护性和可扩展性？

// Person.h
class Person {
public:
    Person(std::string name, int age);
    std::string getName() const;
    int getAge() const;
private:
    std::string _name;
    int _age;
};

// Person.cpp
#include "Person.h"

Person::Person(std::string name, int age)
    : _name(std::move(name)), _age(age) {}

std::string Person::getName() const {
    return _name;
}

int Person::getAge() const {
    return _age;
}

// PersonTests.h
#include "Person.h"

class PersonTests : public testing::Test {
protected:
    Person* person;
};

// PersonTests.cpp
#include "PersonTests.h"

TEST_F(PersonTests, ConstructorAssignsNameAndAge) {
    // 红阶段：测试最初应该失败
    person = new Person("", 0);
    ASSERT_EQ(person->getName(), "John Doe");
    ASSERT_EQ(person->getAge(), 25);

    // 绿阶段：实现 Person 类以使测试通过
    person = new Person("John Doe", 25);
    ASSERT_EQ(person->getName(), "John Doe");
    ASSERT_EQ(person->getAge(), 25);
}