CODEWITHSUNDEEP
c++unit-testingboost
tzippy
tzippy

Reputation: 6638

Boost Unit Test: Catch an unsuccessful Test

I am running a test where a usb device is opened, a packet is sent and received and it is closed again. It looks like this:

void TestCase1(void)
{
 int recv;
 BOOST_REQUIRE(initDevice());
 BOOST_REQUIRE(openDevice());
 BOOST_REQUIRE_EQUAL(receiveData(), 5);
 BOOST_REQUIRE(closeDevice());
 BOOST_REQUIRE(uninitDevice());
}

Now whenever there is an error in the receiveData() call and the Check for '5' fails, the closeDevice() and uninitDevice() are not called anymore and I cannot use the device in the next test. Is there a way to handle this? Maybe catch an exception and close and uninit the device in that catch scope too? Or is this a complete wrong approach? I am pretty new to unit testing. So any help is appreciated. Thanks!

Upvotes: 0

Views: 308

Answers (3)

The Forest And The Trees
The Forest And The Trees

Reputation: 1856

I would use one of the key concepts within modern C++, RAII, to help keep initDevice / uninitDevice and openDevice/closeDevice tied together:

class USBDeviceHandler
{
public: 
    USBDeviceHandler()
    : initDeviceHandle { ::initDevice()), &::uninitDevice },
      openDeviceHandle { ::openDevice()), &::closeDevice }
    {
    }

    using init_handle = std::unique_ptr<void, decltype(&::uninitDevice)>;
    using open_handle = std::unique_ptr<void, decltype(&::closeDevice)>;

    init_handle initDeviceHandle;
    open_handle openDeviceHandle;
};

void TestCase1(void)
{
 int recv;
 USBDeviceHandler device; //init/open is called upon construction
 BOOST_REQUIRE_EQUAL(receiveData(), 5);
}//close/uninit is called upon destruction

This is based off the example given in Rule of Zero.

Upvotes: 2

doctorlove
doctorlove

Reputation: 19232

You might be better off doing things that must happen first in a fixture setup and tidying up in a tear down function. Obviously using OO with RAII and putting the receiveData as a class method would avoid this.
Alternatively, BOOST_CHECK will check the condition and continue the test if it fails which would avoid the problem you have wherein BOOST_REQUIRE stops the rest of the test executing.

Upvotes: 1

John Zwinck
John Zwinck

Reputation: 249133

You should use BOOST_CHECK and BOOST_CHECK_EQUAL when you want to report a condition not being satisfied, yet still continue the test. In this case, perhaps the first two items should be "REQUIRE"d, and the last three should be "CHECK"ed.

Upvotes: 1

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