Test coverage is a very useful metric: it tells how much of your code has been covered by tests. Or the other way: it helps identifying areas of my code which has not been running tests. A new CMake extension in VS Code is available. It works with the new NXP LinkServer test runner to allow running tests on an embedded target. The really cool thing is: it collects and visualizes test data with coverage information in a single step:
The release 24.9.75 of LinkServer software and tools includes interesting feature: the ability to use the debug probe for automated on-target testing. It includes a ‘runner’ which can program, launch and run the application on the target through a debug probe. While the target is running, it uses semihosting or UART for communication. This makes it a perfect tool for automated testing, especially in a CI/CD environment. One such environment is running automated tests with CMake and CTest in VS Code.
SEGGER has released a new version of their J-Link tools suite. That suite includes the J-Run utility which loads, executes and monitors the output of the target. Output can be with RTT (Real-Time Transfer) or semihosting. This makes it useful for automated tests with CMake and CTest:
What has been added from the V7.98g release is the ability to send arguments to the running application using the --args command, for example with CMake/CTest:
set (RUNNER_CTEST_COMMAND "$ENV{SEGGER_PATH}/JRun" --verbose --device LPC55S16 --silent --rtt -if SWD)
add_test(
NAME Led_1
COMMAND ${RUNNER_CTEST_COMMAND} --args "Led_1" ${TEST_EXECUTABLE}
)
Like applications running on the host, I can now pass arguments to the running application. This is useful to set up the target, or to tell which kind of tests to run.
Continue readingOne key element of a CI/CD pipeline is the automatic testing phase: whenever I check in new source code or manually trigger it, I can run a test suite to make sure that the changes do not break anything. For this, I have to run automated tests. For an an embedded target, it means that I have to run some tests on the board itself too.
Unit testing is a common practice for host development. But for embedded development this still seems mostly a ‘blank’ area. Mostly because embedded engineers are not used to unit testing, or because the usual framework for unit testing requires too many resources on an embedded target?
What I have used is the μCUnit framework which is a small and easy to use framework, targeting small microcontroller applications.
uCUnit
MCU on Eclipse 