CMake improvements

[Waqar144]

• Allow disabling tests
• Use CMAKE_CURRENT_SOURCE_DIR when copy JSONTestSuite

[jart]

Thank you for taking the time to send this. I'm reluctant to merge it since I'm not sure what the use case would be aside from development. I just run the makefile. I don't particularly like cmake so I'm only interested in maintaining it insofar as it helps people use the project.

[Waqar144]

The use case is making it easy to embed this library in other projects. From the commit description:

Otherwise if a project embeds this library, it tries to find JSONTestSuite
in its top level CMakeLists.txt directory

By embedding a project I mean adding it as a git submodule or including it using something like CPM. https://github.com/cpm-cmake/CPM.cmake

[jart]

Having good VSCode integration is a good use case. I guess integration is too. However are you planning to do development work on json.cpp? Is this integration for a public project? Could you upstream your improvements?

[Waqar144]

I don't have plans to do development work on this library atm. I am trying to get this library incorporated in a commercial closed sourced project.

This patch is me trying to upstream Cmake changes that make integration via CPM simpler.

On the c++ everything worked without issues so atm I don't have anything to upstream.

[jart]

You do have something to upstream, which is the work you did improving our CMake config. I need you to sync this PR to HEAD and secondly could you have it also delete these three lines (to fix an unrelated compiler crash flake):

json.cpp/.github/workflows/ubuntu.yml

Lines 30 to 32 in cb9d9a1

	- arch: ppc64le
	distro: ubuntu22.04
	platform-name: linux/ppc64le

Then we should be good to go.

[jart]

LGTM