分享本人编写的运行时改变 C++ 函数行为的库 - Injector++

Injector++

Injector++ 可以让您在不改变原有代码的基础上，在运行时改变函数的行为，支持普通函数，虚函数，静态函数等。目前Windows版已基本完成，正在制作Linux版。详情见项目主页

使用说明

Mock 全局函数

std::string fooReturnString()
{
    return "FooReturnString";
}

std::string fakeFooReturnString()
{
    return "FakeFooReturnString";
}

TEST_F(FakeClassNonVirtualMethodTestFixture, FakeGlobalStringFunctionWhenCalled)
{
    // Prepare
    std::string expected = "FakeFooReturnString";
    InjectorPP::Injector injector;

    injector.whenCalled(fooReturnString)
        .willExecute(fakeFooReturnString);

    // Act
    // fakeFooReturnString will be executued!
    std::string actual = fooReturnString();

    // Assert
    EXPECT_EQ(expected, actual);
}

Mock 普通方法

class FakeClassNonVirtualMethodTestFixture : public ::testing::Test
{
public:
    int fakeFunc()
    {
        return 6;
    }
};

TEST_F(FakeClassNonVirtualMethodTestFixture, FakeIntFunctionWhenCalled)
{
    // Prepare
    int expected = 6;
    InjectorPP::Injector injector;

    injector.whenCalled(INJECTORPP_MEMBER_FUNCTION(BaseClassTest::getAnInteger))
        .willExecute(INJECTORPP_MEMBER_FUNCTION(FakeClassNonVirtualMethodTestFixture::fakeFunc));

    BaseClassTest b = BaseClassTest();

    // Act
    // fakeFunc will be executed!
    int actual = b.getAnInteger();

    // Assert
    EXPECT_EQ(expected, actual);
}

Mock 虚函数

int fakeIntFuncForDerived()
{
    return 2;
}

TEST_F(FakeClassVirtualMethodTestFixture, MockDerivedClassVirtualMemberFunctionWhenCalled)
{
    // Prepare
    int expected = 2;
    BaseClassTest* derived = new SubClassTest();

    InjectorPP::Injector injector;
    injector.whenCalledVirtualMethod(derived, "getAnIntegerVirtual")
        .willExecute(fakeIntFuncForDerived);

    // Act
    // fakeIntFuncForDerived() will be exectued!
    int actual = derived->getAnIntegerVirtual();

    // Assert
    EXPECT_EQ(expected, actual);

    delete derived;
    derived = NULL;
}

Mock 静态方法

static Address fakeGetAnAddressStatic()
{
    Address addr;
    addr.setAddressLine("fakeAddressLine");
    addr.setZipCode("fakeZipCode");

    return addr;
}

TEST_F(FakeClassNonVirtualMethodTestFixture, FakeStaticFunctionReturnUserDefinedClassWhenCalled)
{
    // Prepare
    Address expected;
    expected.setAddressLine("fakeAddressLine");
    expected.setZipCode("fakeZipCode");

    InjectorPP::Injector injector;

    injector.whenCalled(INJECTORPP_STATIC_MEMBER_FUNCTION(BaseClassTest::getAnAddressStatic))
        .willExecute(INJECTORPP_MEMBER_FUNCTION(FakeClassNonVirtualMethodTestFixture::fakeGetAnAddressStatic));

    // Act
    // fakeGetAnAddressStatic will be executed!
    Address actual = BaseClassTest::getAnAddressStatic();

    // Assert
    EXPECT_EQ(expected, actual);
}