autoRequire.lua

local mt = setmetatable
local rawset = rawset
local rawget = rawget
local pattern = "([^%.]+)$"

local _autoRequire = function(cls)
    local impl = rawget(cls, "__IMPL")
    if impl == nil then
        impl = require(cls.__RPATH)
        rawset(cls, "__IMPL", impl)
        mt(cls, impl)
    end
    return impl
end

local _autoRequireRoot = {
    __index = function(cls, key)
        local impl = _autoRequire(cls)
        return impl[key]
    end,
    __newindex = function(cls, key, value)
        local impl = _autoRequire(cls)
        impl[key] = value
    end,
    __call = function(cls, ...)
        local impl = _autoRequire(cls)
        return impl(...)
    end
}

local _getModuleName = function(path, moduleName)
    if not moduleName then
        moduleName = string.match(path, pattern) or path
    end
    return moduleName
end

function autoRequire(path, moduleName)
    _G[_getModuleName(path, moduleName)] = mt({__RPATH = path}, _autoRequireRoot)
end