Simple module watcher (for Love2D, but not necessarily - just replace the mtime function)

watch.lua

local m = {}


m.mods = {}


function m.mtime(filepath)
  local info = love.filesystem.getInfo(filepath)
  return info and info.modtime
end


function m.modToPath(modname)
   return modname:gsub('%.', '/') .. '.lua'
end


function m.proxy(modname)
   return function(_, k) return package.loaded[modname][k] end
end


function m.require(modname)
   m.mods[modname] = m.mtime(m.modToPath(modname))
   require(modname)
   local m = {__index=m.proxy(modname)}
   return setmetatable(m, m)
end


function m.update()
   for mod, ts in pairs(m.mods) do
      local fp = m.modToPath(mod)
      local nts = m.mtime(fp)
      if nts ~= ts then
         m.mods[mod] = nts
         print('Reloading ' .. mod)
         local ok, err = pcall(function() package.loaded[mod] = dofile(fp) end)
         if not ok then print('Error: ' .. err) end
      end
   end
end


return m