Commonizing FPrime components

[weggert2]

Hello! I have several components that I'd like to put in their own repository, with their own tests, for re-use by several other projects. These several projects may wish to use different releases of FPrime.

base_project/
    components/
          component1
          component2
    fprime @ release A

A particular vehicle has its own repository

vehicle_1/
    components/
         component3
         component4
    fprime @ release B
    base_project @ release C

Will this cause problems? I want vehicle 1 to use fprime release B, and ignore fprime release A. Also, I'd like to be able to run vehicle 1's unit tests without running all of the base project's unit tests, since the base project will have its own CI.

How have you managed this?

Thank you!

[thomas-bc]

The way we usually manage shared components is through the use of F´ libraries

See a few examples:

• https://github.com/fprime-community/fprime-zephyr
• https://github.com/fprime-community/fprime-arduino

So in your case it could look like

shared_library/
   component1
   component2


base_project/
   [....]
   shared_library@version

vehicle1/
    [....]
    shared_library@version

Using different versions of F´ can work with this approach, as long as your shared components are compatible with both versions.

[weggert2]

How do you test things in your shared library? Noticing that for e.g. in Zephyr there aren't tests

[thomas-bc]

You can define test just like in a regular project, and run them when you include the library in a project. I don't think we are able to run tests outside of a concrete project just yet. But that would definitely be a good feature request.

[weggert2]

Ah yes that's a problem, and current status would be an anti-feature. We don't want vehicle projects to need to run the component library tests; that will take up unnecessary CI time. The shared library will have its own CI, and will run as-needed. Then the vehicle that uses it can trust the component library is tested, and only needs to run its specific tests

So currently that means that the shared library has (or will have, I'm setting this up now) its own fprime checkout, so that we can run tests. Hopefully the vehicle projects that submodule the component library can "ignore" the library's fprime checkout and use their own.