Running Tests#

Utopia contains unit tests to ensure consistency by checking if class members and functions are working correctly. This is done both for the C++ and the Python code. The tests are integrated into the GitLab Continuous Integration pipeline, meaning that tests are run upon every push to the project and failing tests can be easily detected. Tests can also be executed locally, to test a (possibly altered) version of Utopia before committing and pushing changes to the GitLab.

To build all tests, run the following commands:

cmake -DCMAKE_BUILD_TYPE=Debug ..
make -j4 build_tests_all

This first sets the Debug build type as described in the README and then builds all tests. The -j4 argument specifies that four test targets can be built in parallel. It makes sense to adjust this to the number of processors you want to engage in this task.

To then carry out the tests, call the corresponding test_-prefixed target:

make -j4 test_all

Test Groups#

Usually, changes which are to be tested are concentrated in a few files, which makes running all tests with test_all time-consuming and thus inefficient. We therefore provide grouped tests, which relate only to a subset of tests. A group of tests can be built and invoked individually by calling:

make build_tests_<identifier>
make test_<identifier>

Replace <identifier> by the appropriate testing group identifier from the table below.


Test description


Model infrastructure, managers, convenience functions …


Data input and output, e.g. HDF5, YAML, …


Combination of core and dataio


The C++ model tests of model with name <name>


The C++ and Python tests for all models


All python model tests (from python/model_tests)


Tests for utopya frontend package


All of the above. (Go make yourself a hot beverage when invoking this.)


  • Identifiers marked with ‘†’ require all models to be built (by invoking make all before running these tests).

  • Identifiers marked with ‘‡’ do not have a corresponding build_tests_* target.

  • The build_tests_ targets give you more control in scenarios where you want to test only building.

Running Individual Test Executables#

Each individual test also has an individual build target, the names of which you see in the output of the make build_tests_* command. For invoking the individual test executable, you need to go to the corresponding build directory, e.g. build/tests/core/, and run the executable from that directory, as some of the tests rely on auxiliary files which are located relative to the executable.

For invoking individual Python tests, there are no targets specified. However, pytest gives you control over which tests are invoked:

cd python
python -m pytest -v model_tests/{model_name}             # all tests
python -m pytest -v model_tests/{model_name}/  # specific test file

Tests for individual utopya modules need to be run through the python/utopya/ executable rather than through pytest directly:

cd python/utopya
python -v test/{some_glob}                   # selected via glob


For all of the above, make sure you entered the virtual environment and the required executables are all built; call make all to make sure. See pytest --help for more information regarding the CLI.

Evaluating Test Code Coverage#

Code coverage is useful information when writing and evaluating tests. The coverage percentage is reported via the GitLab CI pipeline. It is the mean of the test coverage for the Python code and the C++ code.

For retrieving this information on your machine, follow the instructions below.

Python code coverage#

The Python code coverage is only relevant for the utopya package. It can be analyzed using the pytest-cov extension for pytest, which is installed into the utopia-env alongside the other dependencies. When running make test_utopya, the code coverage is tracked by default and shows a table of utopya files and the lines within them that were not covered by the tests.

If you would like to test for the coverage of some specific part of utopya, adjust the test command accordingly to show the coverage report only for one module, for example utopya.multiverse:

(utopia-env) $ cd python/utopya
(utopia-env) $ python -v test/ --cov=utopya.multiverse --cov-report=term-missing

C++ code coverage#

  1. Compile the source code with code coverage flags.

Utopia provides the CMake configuration option CPP_COVERAGE for that purpose,

cmake -DCPP_COVERAGE=On ..

This will add the appropriate compiler flags to all tests and models within the Utopia framework. Notice that code coverage is disabled for Release builds because aggressive compiler optimization produces unreliable coverage results.

  1. Execute the tests.

Simply call the test commands listed in the previous sections.

  1. Run the coverage result utility gcovr.

First, install it via pip. If you want your host system to be unaffected, enter the Utopia virtual environment first.

pip3 install gcovr

gcovr takes several arguments. The easiest way of using it is moving to the build directory and executing

gcovr --root ../

This will display the source files and their respective coverage summary into the terminal. You can narrow down the report to certain source code paths using the --filter option and exclude others with the --exclude option.

gcovr can give you a detailed HTML summary containing the color coded source code. We recommend reserving a separate directory in the build directory for that matter:

mkdir coverage
gcovr --root ../ --html --html-details -o coverage/report.html

Note that the C++ code coverage can also be evaluated when using the Python test framework to run the tests, because the information is gathered directly from the executable. This makes sense especially for the model tests, where it is sometimes more convenient to test the results of a model run rather than some individual part of it.