Currently Swift Package Manager has the very explicit requirement that source code must be placed within the 'Sources' directory and any test code must be placed within the 'Tests' directory. Attempting to move any test cases into the Sources directory will no longer make the tests executable.
This prevents colocating source code with their tests, in order to be better discoverable and provide a grouping. Especially in large codebases, it can be hard to find their related tests - especially if there are test cases that are not named like the source code but still related. Colocating source code with their tests cases does not only improve discoverability but also requires less context switching and avoids having to manually find the test case somewhere hidden in the tests directory.
For regular Xcode projects this has always worked, as the file's target can be assigned separately within e.g. the Inspector and does not depend on the location of the file on disk. The file's target is stored within the .xcproject file (which, luckily, doesn't exist in SPM).
I imagine three (likely very naive) solutions:
- any source code file that imports the
- any source code files that contain
Testas suffix in their names (this could be potentially dynamic and be specified within the Package manifest, although I'm not sure about the value here and consider the naming recommended)
- utilize the same mechanism that is being used for automatic test discoverability on Linux and Apple Platforms (available since Swift 5.1) for discovering any test cases
For the first and second option, I'd always consider the entire file to belong to the tests.
To be fair, I didn't dig into any of these details, as I would like to first validate my assumption that this is something useful not only for myself. I've been using test colocation for a very long time now and had very good experiences with doing so.
I read @codafi's proposal in 2018 about introducing in-line test annotations and its thread but it seems to be way more complex and ambitious than what I'm asking for. Thanks @briancroom for guiding me here and suggesting to start a thread!
I would love to hear what y'all think and if there's actually any need for this. Please be patient with me, as this is my first contribution on the forums.
I apologize if this is a duplicate, please let me know if it is. I tried my best finding a different topic that pitches the same idea but ultimately failed.