Neovim - Project Local Config with exrc.nvim

.config--hammerspoon--.nvimrc.lua

require("config.lsp.custom").patch_lsp_settings("sumneko_lua", function(settings)
  settings.Lua.diagnostics.globals = { "hs", "spoon" }

  settings.Lua.workspace.library = {}

  local hammerspoon_emmpylua_annotations = vim.fn.expand("~/.config/hammerspoon/Spoons/EmmyLua.spoon/annotations")
  if vim.fn.isdirectory(hammerspoon_emmpylua_annotations) == 1 then
    table.insert(settings.Lua.workspace.library, hammerspoon_emmpylua_annotations)
  end

  return settings
end)

.config--nvim--init.lua

--[[ Modify your Neovim config file ]]

local cwd = vim.fn.getcwd(-1, -1)

if cwd == '/path/to/project-a' then
  -- config for project-a
elseif cwd = '/path/to/project-b' then
  -- config for project-b
end

-----------------

--[[ Built-in Option: `exrc` ]]

vim.o.exrc = true
vim.o.secure = true

-----------------

--[[ Plugin: `exrc.nvim` ]]

vim.o.exrc = false

require("exrc").setup({
  files = {
    ".nvimrc.lua",
    ".nvimrc",
    ".exrc.lua",
    ".exrc",
  },
})

.config--nvim--lua--config--lsp--custom.lua

local mod = {}

---@param server_name string
---@param settings_patcher fun(settings: table): table
function mod.patch_lsp_settings(server_name, settings_patcher)
  local function patch_settings(client)
    client.config.settings = settings_patcher(client.config.settings)
    client.notify("workspace/didChangeConfiguration", {
      settings = client.config.settings,
    })
  end

  local clients = vim.lsp.get_active_clients({ name = server_name })
  if #clients > 0 then
    patch_settings(clients[1])
    return
  end

  vim.api.nvim_create_autocmd("LspAttach", {
    callback = function(args)
      local client = vim.lsp.get_client_by_id(args.data.client_id)
      if client.name == server_name then
        patch_settings(client)
        return true
      end
    end,
  })
end

return mod