Cannot enable linting with eslint on JS files using native nvim lsp.

[mattn]

Cannot enable linting with eslint on JS files using native nvim lsp.

[lukas-reineke]

I don't see anything obvious in your config.

I think know what your problem is, but I don't know why it's happening.
For some reason, Neovim doesn't resolve the filetype correctly when first attaching the buffer to LSP.
Afterwards efm just has an empty string as the languageID, and your config doesn't get resolved. This is an issue with Neovim.

I had the same thing happen as well, but I refactored a bunch of things and it went away. I never figured out what was wrong.
The place in Neovim source is not that complicated https://github.com/neovim/neovim/blob/master/runtime/lua/vim/lsp.lua#L281
really not sure what is causing this.

I think you can close the issue here and open one in Neovim. Or ask in the Gitter channel if someone has an idea.

[stellarhoof]

@mattn Actually it would be very helpful if efm was more chatty. At the very least send the stderr to the server's log file.

Also helpful would be to support different log levels. I see a -loglevel cli option but changing it has no effect on the server log. It would be much easier to debug if I could increase it and see all incoming requests from nvim.

[mattn]

Could you please provide your config.yaml?

[stellarhoof]

Thanks for the prompt response. I don't use a config.yaml, I use the recently added feature for DidChangeConfiguration

[mattn]

What filetype did you open?

[stellarhoof]

javascript

[mattn]

Hmm. I'll look into it tonight.

[mattn]

I could configure with vim-lsp and vim-lsp-settings (LspSettingsEditLocal).

{
    "efm-langserver": {
        "workspace_config": {
            "languages": {
                "javascript": [
                    {
                        "lintCommand": "eslint -f unix --stdin",
                        "lintIgnoreExitCode": true,
                        "lintStdin": true
                    }
                ]
            }
        }
    }
}

[mattn]

You can debug messages from stderr of efm-langserver.

[stellarhoof]

@mattn I don't think I can access the server's stderr since it gets spawned by nvim.

I see that @lukas-reineke added support for DidChangeConfiguration. I copied his example in the readme and it looks like he's also using it on his dotfiles. @lukas-reineke is it working for you?

[lukas-reineke]

your config works fine for me.
Maybe eslint is not in your path?

[lukas-reineke]

LanguageID is empty

I didn't see that at first, this sounds like your nvim LSP is not setup correctly.
can you link your config?

[stellarhoof]

Thanks for the prompt reply. eslint is in my path. I have ./node_modules/.bin in $PATH and eslint is also installed globally so a bare eslint always resolves to the correct one. Here's the relevant section in my dotfiles.

FYI formatting on javascript files (and all other filetypes for that matter) works fine. Also I don't have linting enabled in lua, so I get the correct message 2020/11/30 08:06:35 lint for LanguageID not supported: lua in the efm server logs.

[stellarhoof]

Makes sense. Thanks for the detailed reply @lukas-reineke! I'll investigate on my own and possibly open an issue on nvim.

[disrupted]

@stellarhoof same issue here with the empty LanguageID and it only seems to affect some files. Did you open an issue on neovim or find out what's causing this?