ELP language server seems to ignore .elp_lints.toml (when in IDE)

[JonathanArns]

This is basically a duplicate of #87, but I am opening a new issue, since the original was closed even though the underlying issue is not solved.

I would like some way of selectively enabling/disabling lints project-wide and for all developers working on the project, so I think the workaround of using LSP configuration that was presented in the linked thread does not cut it.

I understand from the thread that some major changes to the configuration mechanism might be needed. @robertoaloi @alanz is this on the roadmap?

[robertoaloi]

@JonathanArns Yes, we expect a lot of config-related changes in Q3 2025, most likely after summer.

[cfclavijo]

I'm using this for Emacs with Eglot

(defvar my/elp-ignored-diagnostic-codes
  '("W0038" "W0051")
  "List of diagnostic codes to ignore in erlang-mode when elp.")

(defun my/eglot-filter-diagnostics (diagnostics)
  "Filter out DIAGNOSTICS with codes in `my/elp-ignored-diagnostic-codes`."
  (when diagnostics
    (seq-remove
     (lambda (fcode)
       (let ((dcode (plist-get
                     (cdr (assoc 'eglot-lsp-diag (flymake-diagnostic-data fcode)))
                     :code)))
         (member dcode my/elp-ignored-diagnostic-codes)))
     diagnostics)))

(defun my/eglot-handle-diagnostics-advice (diagnostics)
  "Filter DIAGNOSTICS before eglot sends them to flymake."
  (let ((filtered (my/eglot-filter-diagnostics (car diagnostics))))
      (setf diagnostics (list filtered))
    diagnostics))

(with-eval-after-load 'eglot
  (advice-add 'eglot--report-to-flymake
              :filter-args #'my/eglot-handle-diagnostics-advice))

[wiserfz]

the .elp_lint.toml file is not effective for elp in neovim, is there any solution?

[belltoy]

Here is a workaround for NeoVim:

First of all, install dharmx/toml.nvim. And then add the following config:

local function load_elp_lint()
  local result = {
    disabled = {},
    enabled = {},
  }
  local cwd = vim.fn.getcwd()
  local file_path = cwd .. "/.elp_lint.toml"
  local toml = require("toml.engine")
  local file = io.open(file_path, "r")

  if not file then
    return result
  end

  local content = file:read("*a")
  file:close()

  local config = toml.decode(content)
  if config.disabled_lints then
    for _, lint in ipairs(config.disabled_lints) do
      table.insert(result.disabled, lint)
    end
  end

  if config.enabled_lints then
    for _, lint in ipairs(config.enabled_lints) do
      table.insert(result.enabled, lint)
    end
  end

  if #result.disabled > 0 then
    local disabled_str = table.concat(result.disabled, ", ")
    notify_fun("Loaded ELP lint config from .elp_lint.toml\nDisabled: " .. disabled_str,
      vim.log.levels.INFO, { title = "ELP Lint" })
  end
  if #result.enabled > 0 then
    local enabled_str = table.concat(result.enabled, ", ")
    notify_fun("Loaded ELP lint config from .elp_lint.toml\nEnabled: " .. enabled_str,
      vim.log.levels.INFO, { title = "ELP Lint" })
  end

  return result
end

require('lspconfig').elp.setup {
  on_attach = on_attach,
  settings = {
    elp = {
      diagnostics = load_elp_lint(),
    }
  }
}

According to the manual-installation