C++单元测试(Unit Test)中Catch和Gmock的结合使用

1. Tutorial of Catch

Chinese version:
http://blog.guorongfei.com/2016/08/22/cpp-unit-test-catch/
Official(recommand, very clear and useful):
https://github.com/philsquared/Catch/blob/master/docs/Readme.md

2. Integrate Catch with Gmock in VS2013

In Short: Write custom main function and involve Gmock code in testcase of Catch in test code.

1. Structure

---

2. Code

1. hello_world.h

#pragma once
#include "messager.h"

class HelloWorld
{
public:
    HelloWorld();
    virtual ~HelloWorld();
    string getMessage(Messager *messager) const;
};

2. messager.h

Class to be mocked.

#pragma once
#include <string>
using namespace std;

class Messager
{
public:
    virtual ~Messager() {}
    virtual string getMessage() = 0;
};

3. mock_messager.h

Mock Messager class.

#pragma once
#include "messager.h"

class MockMessager :public Messager
{
public:
    MOCK_METHOD0(getMessage, string());
};

4. hello_world.cpp

It invokes getMessage() in Messager.

#include "hello_world.h"
#include "messager.h"

HelloWorld::HelloWorld(){}

HelloWorld::~HelloWorld(){}

string HelloWorld::getMessage(Messager *messager) const
{
    return messager->getMessage();
}

5. Test.cpp

For using Gmock, we need to write our own main function to involve
::testing::GTEST_FLAG(throw_on_failure) = true;
::testing::InitGoogleMock(&argc, argv);

Reference:
1. Gmock: Using Google Mock with Any Testing Framework
2. Catch: Supplying your own main()

//Test.cpp
// write your own main function
#define CATCH_CONFIG_RUNNER
#include "catch.hpp"
#include "gmock/gmock.h"
#include "mock_messager.h"
#include "hello_world.h"
#include <String>
using namespace testing;

TEST_CASE("Test Gmock", "[MockMessager]") {
    MockMessager messager;
    std::string msg = "Hello World";
    EXPECT_CALL(messager, getMessage()).WillRepeatedly(Return(ByRef(msg)));
    HelloWorld helloWorld;

    SECTION("HandleGetMessage") {
        //CAPTURE(helloWorld.getMessage(&messager));
        REQUIRE("Hello Worl" == helloWorld.getMessage(&messager));
    }
}

int main(int argc, char* argv[])
{
    // The following line causes Google Mock to throw an exception on failure,
    // which will be interpreted by your testing framework as a test failure.
    ::testing::GTEST_FLAG(throw_on_failure) = true;
    ::testing::InitGoogleMock(&argc, argv);
    // global setup...
    int result = Catch::Session().run(argc, argv);
    // global clean-up...
    system("pause");
    return (result < 0xff ? result : 0xff);
}

6. Result

I intentionally misspell the required word “hello_worl” for showing the fail report.

---

3. Problem

Integrate Catch and Gmock will cause the conflicts of two macros FAIL and SUCCEED. Thank god, these two macros are not necessary, just don't use them :) and can be realized using other macros.
1. FAIL
A macro for log information in Catch. FAIL(message expression), test will fail, if the expression is true.
2. SUCCEED
Not in the tutorial. It’s also a macro for log information.