vim/lua/custom/plugins/nullls.lua

return {
  "jay-babu/mason-null-ls.nvim",
  lazy = false,
  -- event = { "BufReadPre", "BufNewFile" },
  dependencies = {
    "williamboman/mason.nvim",
    "jose-elias-alvarez/null-ls.nvim",
  },
  config = function ()
    require("mason").setup()
    require("mason-null-ls").setup({
      ensure_installed = { 'stylua', 'jq', 'eslint_d' },
      automatic_setup = false,
      automatic_installation = false,
    })
    local nls = require('null-ls')
    local diagnostics = nls.builtins.diagnostics
    local formatting = nls.builtins.formatting
    local code_actions = nls.builtins.code_actions
    local h = require("null-ls.helpers")
    local u = require("null-ls.utils")

    local function eslint_d_cwd(params)
      return u.root_pattern(
        -- https://eslint.org/docs/user-guide/configuring/configuration-files#configuration-file-formats
        ".eslintrc",
        ".eslintrc.js",
        ".eslintrc.cjs",
        ".eslintrc.yaml",
        ".eslintrc.yml",
        ".eslintrc.json"
        -- do not respect package.json
        -- "package.json",
      )(params.bufname)
    end
    require("null-ls").setup({
      debug = true,
      sources = {
        -- Anything not supported by mason.
        diagnostics.eslint_d.with({
          cwd = h.cache.by_bufnr(eslint_d_cwd),
          -- not sure how to scope this only to bcr's locales
          extra_filetypes = { "json" },
        }),
        formatting.eslint_d.with({
          cwd = h.cache.by_bufnr(eslint_d_cwd),
          -- not sure how to scope this only to bcr's locales
          extra_filetypes = { "json" },
        }),
        code_actions.eslint_d.with({
          cwd = h.cache.by_bufnr(eslint_d_cwd),
          -- not sure how to scope this only to bcr's locales
          extra_filetypes = { "json" },
        }),
        code_actions.refactoring,
      },
    })
  end,
}