Cargo.lua Lua Language Server Types

generate_assets_types.lua

local lfs = require("lfs")

local ROOT = "assets"
local OUTPUT = "types/assets.lua"

local typeMap = {
  lua = "function",
  png = "love.Image",
  jpg = "love.Image",
  dds = "love.Image",
  ogv = "love.Video",
  glsl = "love.Shader",
  mp3 = "love.Source",
  ogg = "love.Source",
  wav = "love.Source",
  flac = "love.Source",
  txt = "string",
  fnt = "love.Font",
}

local tree = {}

local function ensure(tbl, key)
  tbl[key] = tbl[key] or {}
  return tbl[key]
end

local function scan(dir, node)
  for file in lfs.dir(dir) do
    if file ~= "." and file ~= ".." then
      local path = dir .. "/" .. file
      local attr = lfs.attributes(path)

      if attr.mode == "directory" then
        local folder = ensure(node, file)
        scan(path, folder)
      else
        local name, ext = file:match("^(.-)%.([^.]+)$")
        if name and ext then
          ext = ext:lower()
          local t = typeMap[ext]
          if t then
            node[name] = t
          end
        end
      end
    end
  end
end

scan(ROOT, tree)

local lines = {}
table.insert(lines, "---@diagnostic disable: missing-fields")
local classes = {}

local function writeClass(name, node)
  -- sorted keys
  local keys = {}
  for k in pairs(node) do
    table.insert(keys, k)
  end
  table.sort(keys)

  -- First, define all nested classes
  for _, k in ipairs(keys) do
    local v = node[k]
    if type(v) == "table" then
      local childName = name .. "_" .. k
      writeClass(childName, v) -- recurse first
    end
  end

  -- Then define this class
  table.insert(classes, "---@class " .. name)
  
  for _, k in ipairs(keys) do
    local v = node[k]

    if type(v) == "table" then
      local childName = name .. "_" .. k
      table.insert(classes, string.format("---@field %s %s", k, childName))
    else
      table.insert(classes, string.format("---@field %s %s", k, v))
    end
  end

  table.insert(classes, "") -- spacing
end

writeClass("GLOBAL_ASSETS", tree)

table.insert(lines, table.concat(classes, "\n"))
table.insert(lines, "---@type GLOBAL_ASSETS")
table.insert(lines, "ASSETS = {}")

local f = assert(io.open(OUTPUT, "w"))
f:write(table.concat(lines, "\n"))
f:close()

print("Generated " .. OUTPUT)

makefile

types:
  # Generate the types for the assets
	lua generate_assets_types.lua

watch:
  # Watch for changes in the assets folder
	sudo watchman-make -p 'assets/**' --run 'make types'

running make watch creates and update the types for https://github.com/bjornbytes/cargo allowing to auto complete new added files.

local cargo = require("lib.cargo")

function love.load()
  ASSETS = cargo.init("assets")
end

The scripts assigns the type to the ASSET Global variable, by the time love.load is executed, any subsequent usages of the ASSETS variable will be already initialize. Cargo.init be called and assigned before the load function if desired (but not recommended).

---@type GLOBAL_ASSETS
ASSETS = {}

Watch function depends on watchman being installed.