C++，Googlemock测试本地对象

Question

我开始使用googletest和googlemock库，我有一个无法解决的问题。我有这样的代码：

class Painter
{
  public:
  void DrawSomething();
};

void Painter::DrawSomething()
{
  Turtle turtle;
 turtle.doSomething();
}

main()
{
  Painter p;
  p.DrawSomething();
}

我已经模拟了Turtle类，但是在本地创建海龟对象时，如何测试doSomething()方法(例如使用EXPECT_CALL)？不修改Painter类是可能的吗？

谢谢你的回答。

Answer 1

我编写了一个包装类来模拟生产代码，而不更改它。如果有什么瑕疵，请告诉我。

#include "gtest/gtest.h"
#include "src/gtest-all.cc"
#include "src/gmock-all.cc"
#include "src/gmock_main.cc"
#include <iostream>
#include <string>
#include <vector>

using ::testing::An;
using ::testing::AtLeast;
using ::testing::DoAll;
using ::testing::NotNull;
using ::testing::Return;
using ::testing::ReturnRef;
using ::testing::SetArgReferee;

using namespace std;

class Student
{
    int iAge;

    public:
    Student(int _iAge) : iAge(_iAge)
    {
    }

    virtual void PrintDetails()
    {
        cout<<"Age:"<<iAge<<endl;
    }
    virtual bool CheckGrade(int iGrade)
    {
        return (iGrade - 5) == iAge;
    }
};

class StudentFaker
{
    static Student* internalObject;

    public:

    static void FakerSetObject(Student* object) {
        internalObject = object;
    }

    StudentFaker(int _iAge){
    }

    void PrintDetails()  {
        internalObject->PrintDetails();
    }

    bool CheckGrade(int iGrade)  {
        return internalObject->CheckGrade(iGrade);
    }
};

Student* StudentFaker::internalObject = NULL;

class StudentMock : public Student
{
    public:
    StudentMock(int _iAge) : Student(_iAge) { }

    MOCK_METHOD0(PrintDetails,void());
    MOCK_METHOD1(CheckGrade,bool(int));
};

#define UNITTEST

bool ProductionCode();

TEST(STUDENT,TEST)
{
    StudentMock stMock(8);

    EXPECT_CALL(stMock, PrintDetails())
        .Times(AtLeast(1))
        .WillOnce(Return());

    EXPECT_CALL(stMock, CheckGrade(5))
        .Times(AtLeast(1))
        .WillOnce(Return(true));

    StudentFaker::FakerSetObject(&stMock);

    EXPECT_TRUE(ProductionCode());
}

//Production code
#ifdef UNITTEST
#define Student StudentFaker
#endif

bool ProductionCode()
{
    Student st(8);
    st.PrintDetails();
    if(st.CheckGrade(5))
        return true;
    else
        return false;
}

//Production code