Parsing tests freezes Neovim and uses a lot of memory (sometimes crashes)

[jfpedroza]

I started working a Neotest adapter for Elixir here. I added parsing of tests and when I run require("neotest").run.run() or require("neotest").summary.open(), Neovim freezes and starts using more and more memory, up to about 4.2 GB.

When it doesn't crash, I can see the test tree. When I run it using stable (0.7.2), I can see the tree in just a second.

I tried using the minimal.lua from the issue template, but it works properly (even takes less than stable).

Any pointers to reproduce the issue would be appreciated.

[rcarriga]

Great to hear you're working on an adapter!

When it doesn't crash, I can see the test tree. When I run it using stable (0.7.2), I can see the tree in just a second.

Interesting, so you're saying that with the exact same setup that stable works but nightly results in a crash? If so, have you tried a newer nightly?

Since you can't reproduce with the minimal init file, the only thing would be to bisect your config until you find the issue. The log file may have some useful information but can't guarantee.

[jfpedroza]

I unsuccessfully tried to find what was causing the issue 😢. It's quite weird.

I removed every file in after/plugin and ran Neovim with nvim -u NORC (so, only the plugins) and could reproduce the issue.

Then I took the minimal.lua file and added every plugin and couldn't reproduce it that way.

My config is in https://github.com/jfpedroza/dotfiles/tree/master/nvim, if you want to give it a try.

[jfpedroza]

Sooo, this was fixed in the last two days. Not sure if it was a change in Neovim nightly or Neotest, but it now behaves properly.

[rcarriga]

Interesting, there were some performance improvements to the the treesitter parsing. I wonder if it had any effect. Can you try passing fast = false to the options table for parse_positions here https://github.com/jfpedroza/neotest-elixir/blob/master/lua/neotest-elixir/init.lua#L104 and see if it makes a difference?

[jfpedroza]

Indeed, setting fast = false returns the problem.

[rcarriga]

Ah OK! So what changed is that internally neovim by default, loads injections for the every treesitter tree. These are not needed for neotest and they slowed down the parsing because they're files that need to be read, so I've disabled them being read. I'm guessing that the injections for elixir caused the parser to perform poorly in some way. Either way great to hear it's fixed!