fix: opening summary window freezes when subprocess finds swap file

[luismeyer95]

Hi! 👋

I've been having a bug for a while which happened seemingly randomly: sometimes when toggling the test summary window, Neovim would freeze completely, forcing a kill + restart of the process.

Steps were the following:

• nvim
• :lua require('neotest').summary.toggle()
• freeze happens

I found the hanging line with some trial and error, subprocess.lua:41 which tries to load neotest in the nvim subprocess and blocks until it gets a response. The fix I found is to spawn the nvim subprocess with swap files disabled.

I have the Shatur/neovim-session-manager plugin installed, and it is configured (by default) to open the last opened session when running nvim without providing a file/dir argument. At some point after toggling the summary window, the nvim subprocess is spawned with nvim --embed --headless re-using the user's config. What I suspect is happening: this subprocess will open the last opened session and open the same files as the main instance, which causes it to error on swap file conflicts and somehow prevent the RPC call to complete. -n nvim CLI flag tells the subprocess to ignore swap files, and after including it + manual testing I've seen no freeze yet with the above scenario.

I tried to reproduce the freeze in other ways, by editing my nvim config to throw errors on startup only for the subprocess, but no freeze with those scenarios.

[rcarriga]

Nice thank you! 😄