Find per-platform binaries for v12.0.0-alpha.13+

[mediremi]

rescript-lang/rescript#7395 split binaries into optional platform-specific dependencies (e.g. @rescript/linux-x64).

I've updated utils.findPlatformPath (used by utils.findBscExeBinary and utils.findEditorAnalysisBinary) to look for these platform-specific dependencies if node_modules/rescript/{platform} doesn't exist.

[zth]

Thank you! 😄

@cometkim can you have a quick look at this one?

[cometkim]

Can't we use rescript as an API?

If we already know the directory, we can use it as an API like:

const { binPaths } = await import('../path/to/rescript package')
binPaths.bsc_exe // should point to the binary path

[mediremi]

The reason why I didn't go with the dynamic import approach is that findPlatformPath and its upstreams (e.g. utils.findBscExeBinary->server.openedFile->server.onMessage) are all synchronous functions and that making them async would likely be an extensive refactor.

I think that copying the import path logic of @rescript/${process.platform}-${process.arch} from cli/common/bins.js is a good pragmatic short-term solution, and a refactor to make the relevant functions async can be done later.

[nojaf]

The entire LSP server is riddled with short-term fixes. I would recommend taking the plunge and going for the asynchronous rewrite. I've encountered this limitation before, and I genuinely believe it's the best approach. @zth, what are your thoughts?

[zth]

@mediremi would it be possible for you to do a quick assessment on how much work it'd be to do the async refactor? At some point we'll need to bite the bullet for sure. But whether it's best to do it now or later is not clear to me right now.