---@type vim.lsp.Config
--- 'root_dir' is chosen like this:
--- if two or more directories containing `mix.exs` were found when searching
--- directories upward, the second one (higher up) is chosen, with the
--- assumption that it is the root of an umbrella app. Otherwise the directory
--- containing the single mix.exs that was found is chosen.
return {
    -- cmd when installing with Mason
    -- Had to install elixir and asdf (homebrew)
    -- Then ran `mix local.hex` to upgrade Hex
    cmd = { vim.env.HOME .. "/.local/share/nvim/mason/packages/elixir-ls/language_server.sh" },
    -- cmd = { "/Users/oliver.ladner/.local/share/nvim/mason/packages/elixir-ls/language_server.sh" },
    filetypes = { "elixir", "eelixir", "heex", "surface" },
    root_dir = function(bufnr, on_dir)
        local fname = vim.api.nvim_buf_get_name(bufnr)
        local matches = vim.fs.find({ "mix.exs" }, { upward = true, limit = 2, path = fname })
        local child_or_root_path, maybe_umbrella_path = unpack(matches)
        local root_dir = vim.fs.dirname(maybe_umbrella_path or child_or_root_path)

        on_dir(root_dir)
    end,
}