Skip to content

Latest commit

 

History

History
108 lines (91 loc) · 4.95 KB

UnitTests.md

File metadata and controls

108 lines (91 loc) · 4.95 KB

Unit Testing in OAI

OpenAirInterface uses ctest for unit testing. The cmake documentation has a tutorial explaining how to test with cmake and ctest; it is a suggested read, and the following just lists the main points of how to compile the tests and how to add new ones.

At the time of writing, only the NR RLC tests have been integrated. The author hopes that more tests follow suit.

How to compile tests

To compile only the tests, a special target tests is available. It has to be enabled with the special cmake variable ENABLE_TESTS:

cd openairinterface5g
mkdir build && cd build # you can also do that in cmake_targets/ran_build/build
cmake .. -GNinja -DENABLE_TESTS=ON
ninja tests

Then, you can run ctest to run all tests:

$ ctest
Test project /home/richie/w/ctest/build
    Start 1: nr_rlc_tests
1/1 Test #1: nr_rlc_tests .....................   Passed    0.06 sec

100% tests passed, 0 tests failed out of 1

Total Test time (real) =   0.06 sec

A couple of interesting variables are --verbose, --output-on-failure.

How to add a new test

As of now, there is no dedicated testing directory. Rather, tests are together with the sources of the corresponding (sub)system. The generic four-step process is

  1. Guard all the following steps with if(ENABLE_TESTS). In a world where OAI is tested completely, there would be many executables that would be of tangential interest to the average user only. A "normal" build without tests would result in less executables, due to this guard.
  2. Add an executable that you want to execute. In a CMakeLists.txt, do for instance add_executable(my_test mytest.c) where mytest.c contains main(). You can then build this executable with ninja/make my_test, given you ran cmake -DENABLE_TESTS=ON ... before.
  3. Create a dependency to tests so that triggering the tests (ninja/make tests) target will build your test: add_dependencies(tests my_test).
  4. Use add_test(NAME my_new_test COMMAND my_test <options>) to declare a new test that will be run by ctest under name my_new_test.

In the simplest case, in an existing CMakeLists.txt, you might add the following:

if(ENABLE_TESTS)
  add_executable(my_test mytest.c)
  add_dependencies(tests my_test)
  add_test(NAME my_new_test COMMAND my_test) # no options required
endif()

Note that this might get more complicated, e.g., typically you will have to link some library into the executable with target_link_libraries(), or pass some option to the test program.

ctest decides if a test passed via the return code of the program. So a test executable that always passes is int main() { return 0; } and one that always fails int main() { return 1; }. It is left as an exercise to the reader to include these examples into ctest. Other programming languages other than C or shell scripts are possible but discouraged. Obviously, though, a test in a mainstream non-C programming language/shell script (C++, Rust, Python, Perl) is preferable over no test.

Let's look at a more concrete, elaborate example, the NR RLC tests. They are located in openair2/LAYER2/nr_rlc/tests/. Note that due to historical reasons, a test script run_tests.sh allows to run all tests from that directory directly, which you might also use to compare to the cmake/ctest implementation.

  1. Since the tests are in a sub-directory tests/, the inclusion of the entire directory is guarded in openair2/LAYER2/nr_rlc/CMakeLists.txt (in fact, it might in general be a good idea to create a separate sub-directory tests/!).
  2. The NR RLC tests in fact consist of one "test driver program" (test.c) which is compiled with different "test stimuli" into the program. In total, there are 17 stimuli (test1.h to test17.h) with corresponding known "good" outputs after running (in test1.txt.gz to test17.txt.gz). To implement this, the tests/CMakeLists.txt creates multiple executables nr_rlc_test_X via the loop over TESTNUM, links necessary libraries into the test driver and a compile definition for the test stimuli.
  3. For each executable, create a dependency to tests.
  4. Finally, there is a single(!) ctest test that runs all the 17 test executables at once(!). If you look at the shell script exec_nr_rlc_test.sh, you see that it runs the program, filters for TEST, and compares with a predefined output from each test in testX.txt.gz, which is gunziped on the fly... Anyway, the actual add_test() definition just tells ctest to run this script (in the source directory), and passes an option where to find the executables (in the build directory). This slight complication is due to using shell scripts. An easier way is to directly declare the executable in add_test(), and ctest will locate and run the executable properly.