How to integrate googletest to stm32 cmake project

Question

I made my project, which I created with STM32 cubeIDE, compilable with Cmake, but I had problems with googletest integration.

The file structure of the entire project is as follows;

Project Link

I created the project and test folders as two different cmake projects. I don't have any problems compiling the project, but I could not establish a healthy connection between the test and the project. Because when compiling the test I get an error.

When I add the source and header files related to the Project to the CmakeList.txt in the test, I get an error in the project's variables and type definitions.

The cmake commands I used in the test file directory are as follows;

$cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_TOOLCHAIN_FILE=<path_to_Project/cmake/gcc-arm-none-eabi.cmake> -S<path_to_Test> -B<path_to_Test/build/Debug> -G Ninja

$cmake --build <path_to_Test/build/Debug> -j 8

Errors;

Do you have any advice to integrate googletest into existing cmake project?

Answer 1

Unless you plan to run the unit tests on the target device (MCU), you cannot and should not include any microcontroller-specific code, such as HAL.

Here are the some approaches for unit testing embedded projects:

• Separate testable code into libraries. This code should not rely on any hardware-specific stuff. Then you can unit-test the library independently.
• If you need to test code that relies on peripherals, you need to abstract the peripherals and create mocks for use in unit tests. This is quite a lot of work to implement and maintain.

Not every piece of code is meant to be unit tested, do some more research to get a better idea of different test types.

Update

So the goal is to run the tests on the target. In that case, I would recommend choosing a different testing framework, as gtest is probably too big to fit on a MCU, even if you could somehow compile it.

I know someone who used cmocka for this purpose. The flow would be something like this:

1. Set-up your code to output the test results through, for example, a serial port.
2. Compile your tests for the MCU.
3. Upload the test firmware to the MCU.
4. Run the tests and examine the output.