Mock non-virtual method giving compilation error

Question

I need to write the gtest to test some existing code that has a non-virtual method, hence I am testing using the below source, but I am getting the compilation error

Answer 1

If you don't want to change your source code, you can leverage injector++. Currently it only supports x86 Windows. But Linux and x64 Windows support will come soon. Below examples will give you a brief idea:

Mock non-virtual methods

Below example fakes BaseClassTest::getAnInteger() by using fakeFunc():

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 virtual methods

Injector++ supports virtual method mocking (Amazing, huh?). Below is a simple example:

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 static methods

Injector++ supports static method mocking. Below is a simple example:

Address FakeGetAnAddress()
{
    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::fakeGetAnAddress));

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

    // Assert
    EXPECT_EQ(expected, actual);
}