[Discussion] Migration of testing framework from doctest to googletest

[mcbarton]

The following PR in CppInterOp compiler-research/CppInterOp#483 has shown GoogleTest to be a testing framework that works for both native and Emscripten builds (testing the Emscripten builds via node). Therefore switching from Doctest to GoogleTest would be beneficial, as it would allow for automated testing in both environments, and check that no changes to improve native builds, breaks the Emscripten build. It will also allow reviewers to check PRs more easily which claim to enable new features for xeus-cpp-lite, or whether a new feature being added for the native builds also works for the Emscripten build.

[SylvainCorlay]

From the Xeus team.

We were originally gtest users, but gtest is not very well maintained. We had reported obvious bugs with the maintainers and proposed fixes which were unfortunately ignored. This is the reason why we switched to doctest.

I also think that using the same framework and making xeus kernels as homogeneous as possible will also help long term sustainability and maintenance.

(For example, we will soon release xeus 6.0. If the changes are the same on all xeus kernels, it will make everyone's life easier.)

[anutosh491]

And I think now that xeus-cpp-lite can be tested pretty smoothly through doctest hosted on emscripten-forge as shown in #277 ... migration for the lite use case might not be hugely relevant unless gtest shows any concrete superior advantages.

mind that gtest is also hosted on emscripten-forge so not eliminating that as an option if it proves better in the future.