Unit Tests Manual


maxon::UnitTestInterface provides an unified interface for any kind of unit test. Such an unit test should verify the correct functionality of every component of a program. Unit tests implemented this way are automatically executed when Cinema 4D starts and unit tests are enabled.


Custom unit test are created by implementing a custom class based on maxon::UnitTestComponent. This custom class must implement maxon::UnitTestInterface::Run() which contains the unit test code.

The result of a test can be printed to the console using a standard format:

A (long running) unit test may be cancelled from the outside:

To measure time for speed tests one can use maxon::TimeValue.
// This example shows a unit test that checks a custom class.
class SimpleMathsUnitTest : public maxon::UnitTestComponent<SimpleMathsUnitTest>
// test constructor / SimpleMaths::GetNumber()
const maxon::Int number = 5;
const SimpleMaths baseTest(number);
const maxon::Result<void> baseRes = baseTest.GetNumber() == number ? maxon::OK : maxon::UnitTestError(MAXON_SOURCE_LOCATION, "GetNumber() failed"_s);
self.AddResult("GetNumber() test"_s, baseRes);
// if GetNumber() fails the rest of the unit tests cannot succeed
if (baseRes.GetError())
return baseRes;
// test SimpleMaths::AddNumber()
SimpleMaths addTest(99);
const maxon::Result<void> addTestRes = addTest.GetNumber() == 100 ? maxon::OK : maxon::UnitTestError(MAXON_SOURCE_LOCATION, "AddNumber() failed"_s);
self.AddResult("AddNumber() test"_s, addTestRes);
// test SimpleMaths::SubstractNumber()
SimpleMaths subTest(100);
const maxon::Result<void> subTestRes = subTest.GetNumber() == 99 ? maxon::OK : maxon::UnitTestError(MAXON_SOURCE_LOCATION, "SubstractNumber() failed"_s);
self.AddResult("SubstractNumber() test"_s, subTestRes);
return maxon::OK;

The result of this unit test will be printed to the console:

@Running unit test 1 / 1: net.example.unittest.simplemaths
Unittest "net.example.unittest.simplemaths" OK: GetNumber() test
Unittest "net.example.unittest.simplemaths" OK: AddNumber() test
Unittest "net.example.unittest.simplemaths" OK: SubstractNumber() test
Duration: 0.5 ms
@ScriptRef End


Different kinds of unit tests can be registered at these registries:

  • maxon::UnitTestClasses: Basic unit tests. This kind of test should pass within seconds. Started with the command line argument "g_runUnitTests".
  • maxon::SpeedTestClasses: Speed tests. This kind of test should pass within seconds. Started with the command line argument "g_runSpeedTests".
  • maxon::LongRunTestClasses: Long run tests. Started with the command line argument "g_runLongRunTests".

To run all unit tests set the command line argument to "*" like g_runUnitTests=*. To run a specific test one can define a filter like g_runUnitTests=*simplemaths*.

// This example registers the given unit test at the registry maxon::UnitTestClasses.
MAXON_COMPONENT_CLASS_REGISTER(SimpleMathsUnitTest, maxon::UnitTestClasses, "net.maxonexample.unittest.simplemaths");

Further Reading