Expect call returning a reference

[RusYus]

I have an interface with a method that returns a reference to itself

struct IDmChecker
{
    virtual IDmChecker& setValuesForInstance(const std::string& a_instanceId) = 0;
};

and mock struct

struct DmCheckerMock : IDmChecker
{
    MAKE_MOCK1(setValuesForInstance, IDmChecker& (const std::string& a_instanceId), override);
};

I have a compilation error when using REQUIRE_CALL:

BOOST_AUTO_TEST_CASE(ShouldNotChangeOnSameValue)
{
...
    DmCheckerMock checker;
    REQUIRE_CALL(checker, setValuesForInstance(_)).RETURN(std::ref(checker));
...
}

1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): error C2662: 'Tests::Main::DmCheckerMock &Tests::Main::DmCheckerMock::trompeloeil_self_setValuesForInstance(const std::string &)': cannot convert 'this' pointer from 'const Tests::Main::DmCheckerMock' to 'Tests::Main::DmCheckerMock &'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): message : Conversion loses qualifiers
1>C:\Dev\sipphone\test\SipPhoneTests\main\DmCheckerMock.h(14,5): message : see declaration of 'Tests::Main::DmCheckerMock::trompeloeil_self_setValuesForInstance'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): error C2955: 'trompeloeil::call_validator_t': use of class template requires template argument list
1>C:\Dev\external\tools\_FOSS\trompeloeil\include\trompeloeil.hpp(4213): message : see declaration of 'trompeloeil::call_validator_t'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): error C2662: 'IDmChecker &Tests::Main::DmCheckerMock::setValuesForInstance(const std::string &)': cannot convert 'this' pointer from 'const Tests::Main::DmCheckerMock' to 'Tests::Main::DmCheckerMock &'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): message : Conversion loses qualifiers
1>C:\Dev\sipphone\test\SipPhoneTests\main\DmCheckerMock.h(14,5): message : see declaration of 'Tests::Main::DmCheckerMock::setValuesForInstance'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): error C2662: 'Tests::Main::DmCheckerMock::trompeloeil_l_tag_type_trompeloeil_14 Tests::Main::DmCheckerMock::trompeloeil_tag_setValuesForInstance(const std::string &)': cannot convert 'this' pointer from 'const Tests::Main::DmCheckerMock' to 'Tests::Main::DmCheckerMock &'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186,5): message : Conversion loses qualifiers
1>C:\Dev\sipphone\test\SipPhoneTests\main\DmCheckerMock.h(14,5): message : see declaration of 'Tests::Main::DmCheckerMock::trompeloeil_tag_setValuesForInstance'
1>C:\Dev\sipphone\test\SipPhoneTests\main\CSipSoftPhone_ManagerTestsFixture.cpp(186): error C2062: type 'unknown-type' unexpected

[rollbear]

Since you use RETURN, the variable checker is captured by value which is const in the body of the RETURN expression. You probably want to use LR_RETURN here, to ensure that you return a reference to the instance and not a copy of it.

See: https://godbolt.org/z/cWvfrMeYv

[RusYus]

Thanks, it works now!