Moving lua code into subdirectory

Question

I want to move all .lua files into the subdirectory code to avoid polluting the main directory with them. However, I cannot get lualatex to find them there.

Given this project layout:

main.tex
main.lua
code/
  test.lua
  test2.lua

main.tex

\documentclass{article}

\directlua{package.path = './code/?.lua;' .. package.path}
\directlua{print(package.path)}
\directlua{require('test')}
\directlua{require('code/test')}

\begin{document}
\end{document}

main.lua

package.path = './code/?.lua;' .. package.path
print(package.path)
require('test')
require('code/test')

code/test.lua

require('test2')

code/test2.lua

print('success')

When I run lualatex main.tex I get the output:

This is LuaTeX, Version beta-0.79.1 (TeX Live 2014/Arch Linux) (rev 4971) 
 restricted \write18 enabled.
(./main.tex
LaTeX2e <2014/05/01>
Babel <3.9k> and hyphenation patterns for 79 languages loaded.
(/usr/share/texmf-dist/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/share/texmf-dist/tex/latex/base/size10.clo))./code/?.lua;/usr/local/share/lua/5.2/?.lua;/usr/local/share/lua/5.2/?/init.lua;/usr/local/lib/lua/5.2/?.lua;/usr/local/lib/lua/5.2/?/init.lua;./?.lua

! LuaTeX error [\directlua]:1: module 'test' not found:
        no field package.preload['test']
        [kpse lua searcher] file not found: 'test'
        [kpse C searcher] file not found: 'test'
stack traceback:
        [C]: in function 'require'
        [\directlua]:1: in main chunk.
l.5 \directlua{require('test')}

? q
OK, entering \batchmode

The problem seems to be that lualatex does not find the files in the subdirectory although I altered the package.path (which is also printed correctly!).

When I runt the same code via lua main.lua the output is

./code/?.lua;/usr/share/lua/5.2/?.lua;/usr/share/lua/5.2/?/init.lua;/usr/lib/lua/5.2/?.lua;/usr/lib/lua/5.2/?/init.lua;./?.lua
success

as expected.

For some reason lualatex seems not to take package.path into account.

Using require('code/test.lua') is not an option because then the dependency between test.lua and test2.lua is not picked up correctly.

What do I need to do to make lualatex find my .lua files in the code directory?

I already followed this question to this answer but I don't see how this solves the problem (or does it state that we cannot change the package search path in lualatex?). Also, the scenario seems to be another one as I don't want to "install a systemwide" module but some scripts for this project only.

Answer 1

The fastest way I have found to import relative packages in lualatex is

require(package.searchpath('test', './?.lua:./code/?.lua'))

which will find test.lua by searching ./ and ./code. It is hacky, but also clear and quick.

Adding the path loader as in https://tex.stackexchange.com/a/219228/2891 is the more thorough solution, but that code did not immediately work for me, plus it would require figuring out the textmf lua paths.

Answer 2

local oldreq = require
require = function(p) 
    return oldreq(package.searchpath(p, './?.lua;./code/?.lua'))
end