fix: add pylyzer dependency info (erg) (#3433)

[fishBone000]

Pylyzer requires Erg as dependency. This info is missing in default config and doc.

[fishBone000]

Opened this PR as a fixer to #3441 (update the file in /lsp/ instead of /lua/lspconfig/...)

[justinmk]

no such thing in vim.lsp.config. try before_init ? and please test that it actually works.

[lithammer]

Hmm, why not just define it directly in cmd_env instead? Something like this:

return {
  cmd = { 'pylyzer', '--server' },
  cmd_env = {
    ERG_PATH = vim.env.ERG_PATH or vim.fs.joinpath(vim.uv.os_homedir(), '.erg')
  },
  ...
}

[justinmk]

Sure, though that means the CWD "sticks" and won't dynamically update. I don't use this config so I have no strong opinion :)

[lithammer]

I mean it wasn't really doing anything dynamic anyway. It was essentially just setting ERG_PATH=~/.erg. Unless I'm missing something...?

And before_init happens after starting the binary. So setting cmd_env wouldn't have any effect?

[justinmk]

before_init happens after starting the binary

oh. Then cmd should be defined as a function (again, assuming this functionality is important for users of this config)

I'm also fine with your cmd_env suggestion.

[lithammer]

before_init happens after starting the binary

oh. Then cmd should be defined as a function (again, assuming this functionality is important for users of this config)

I'm not sure about this though. Just going by the docs:

Callback invoked before the LSP "initialize" phase, where params contains the parameters being sent to the server and config is the config that was passed to vim.lsp.start(). You can use this to modify parameters before they are sent.

Seems to indicate that vim.lsp.start() has already been called.

[lithammer]

With that said. I suppose cmd being a function could be useful when you want to start a server relative to the resolved root.

For example you might want to call ./node_modules/.bin/biome relative to that root.

Though I suppose that could also be solved by having relative paths be relative to workspace root instead of cwd (though relative paths aren't supported at all at the moment I think?).

Or do the VS Code way (or CoC, don't remember which). By using some magic marker like {root_dir}/node_modules/.bin/biome.

[fishBone000]

Fixed, tested and it works.

Not sure what's about the CWD you were talking about though? I kind of get the idea but can't see how it's related to this pylyzer config?

[lithammer]

Not sure what's about the CWD you were talking about though? I kind of get the idea but can't see how it's related to this pylyzer config?

Yeah sorry. I digressed.