Unit Tests

Testing a Stage

If you wrote a new Stage or you added to it’s functionality, you should probably test if it behaves as expected in all the possible cases. To do this you can write a test using pytest and various tools from runner.py like in the following example.

Example

Example test tests/test_<name>.py:

import pytest
from kotekan import runner

# this is the equivalent of the pipeline config file for kotekan to run your test
params = {
    "num_elements": 7,
    "num_ev": 0,
    "total_frames": 128,
    "cadence": 10.0,
    "mode": "default",
    "variable_my_stage_needs": -1,
}

# this runs kotekan and yields the data you want to inspect
@pytest.fixture(scope="module")
def data(tmpdir_factory):

    # keep all the data this test produces in a tmp directory
    tmpdir = tmpdir_factory.mktemp("name_of_the_test_case")

    # you can use FakeVisBuffer as a mock producer stage
    # to produce a Kotekan buffer with fake data
    fakevis_buffer = runner.FakeVisBuffer(
        num_frames=params["total_frames"], mode=params["mode"]
    )

    # DumpVisBuffer can be used to dump data
    # afterwards for asserting expectations
    dump_buffer = runner.DumpVisBuffer(str(tmpdir))

    # KotekanStageTester is used to run your
    # kotekan stage with your config
    # Replace stage_type with the name of your stage
    test = runner.KotekanStageTester(
        stage_type="stageUnderTest",
        stage_config={},
        buffers_in=fakevis_buffer,
        buffers_out=dump_buffer,
        global_config=params,
    )

    test.run()

    # here the data that the stage under test
    # put out is passed on to test the stage
    yield dump_buffer.load()


# this is the actual test (give a name to it)
def test_<name>(data):

    for frame in data:
        assert frame.vis == {1, 0}

• You can run your test with pytest tests/test_<name>.py

Testing a C++ Function

If you want to test a single C++ Function, you can write a test using the Boost Unit Testing Framework as demonstrated by the following example.

Example

• Write a test like this one (Replace <name> with what you are testing):

Example test tests/boost/test_<name>.cpp:

#define BOOST_TEST_MODULE "test_<name>"

#include <boost/test/included/unit_<test>.hpp>

// include the code you want to test:
#include "<name>.hpp"

// Split your tests into test cases
BOOST_AUTO_TEST_CASE(_some_useful_test_case_name) {
    BOOST_CHECK_EQUAL(function(1), 1);
    BOOST_CHECK_EQUAL(function(6), 42);
    BOOST_CHECK_EQUAL(function(26), 4861946401452);
}

• Add add_executable(test_<name> test_<name>.cpp) and target_link_libraries(test_<name> PRIVATE <all_used_libs>) to /tests/boost/CMakeLists.txt.

• Build kotekan with the cmake option -DWITH_BOOST_TESTS=ON under /kotekan/build.

• Make sure pytest-cpp is installed.

• Run your test with pytest tests/boost/test_<name>.