Very crude nu overlay provider for overseer.nvim. It doesn't take arguments so only works on nu defs that don't have args. It only looks for env.nu at the root of the project

overseer-nu_provider.lua

local overseer = require('overseer')
local nushell = require('mtb.nushell')
local mtb_shell = require('mtb.utils.shell')

---@type overseer.TemplateFileDefinition
local tmpl = {
  name = 'nushell',
  priority = 60,
  params = {
    name = { type = 'string', optional = true, default = 'no name' },
    cmd = { type = 'string' },
    args = { optional = true, type = 'list', delimiter = ' ' },
    cwd = { optional = true },
  },
  builder = function(params)
    return {
      name = params.name,
      cmd = { params.cmd },
      args = params.args,
      cwd = params.cwd,
      -- NOTE: echo.notify is an overseer component similar to the builtin notify 
      -- but for echo.nvim, a plugin to add audio to neovim.
      -- this requires my plugin echo: https://github.com/melMass/echo.nvim
      -- components = { { 'unique', replace = true }, { 'echo.notify' }, 'default' },
    }
  end,
}

return {
  condition = {
    callback = function(params)
      local env = vim.fn.filereadable('env.nu')
      return env ~= 0
    end,
  },

  -- this is run once or whenever the cache_key changes
  generator = function(search, cb)
    local lines, err = mtb_shell.execute('overlay use env.nu;scope modules | last | get commands | get name| to text')
    local overlay_cmds = {}
    if not lines then
      print('Error:', err)
    else
      for _, line in ipairs(lines) do
        table.insert(overlay_cmds, line)
      end
    end

    local ret = {}

    for _, cmd in ipairs(overlay_cmds) do
      table.insert(
        ret,
        overseer.wrap_template(tmpl, { name = cmd }, { name = cmd, cmd = 'nu', args = { nushell.custom_configs, "-c 'overlay use env.nu;" .. cmd .. "'" } })
      )
    end
    cb(ret)
  end,
  cache_key = function(opts)
    return vim.fn.getcwd() .. '/env.nu'
  end,
}