Local LuaRocks-based template

Lots of people want LuaRocks to function like npm. While LuaRocks provides some playful ideas for supporting per-project workflows, I'm taking a stab with wrapper scripts.

Requirements

• sh
• luarocks

Explanation

Lua looks for modules in according to the environment variables LUA_PATH and LUA_CPATH. All I'm doing is setting that with a couple shell scripts. I'm sure adapting this for Windows is simple, but as I never use PowerShell or batch files for anything, this project is restricted to Linux. In my case, I'm using Windows Subsystem for Linux.

LUA_PATH and LUA_CPATH values

This is where the supplied wrappers will instruct Lua to search for modules.

• LUA_PATH
  • <project_path>/lua/?.lua
  • <project_path>/lua/?/init.lua
  • <project_path>/lua_modules/share/lua/5.1/?.lua
  • <project_path>/lua_modules/share/lua/5.1/?/init.lua
  • $LUA_PATH
• LUA_CPATH
  • <project_path>/lua_modules/lib/lua/5.1/?.so;
  • $LUA_CPATH

For more information on these environment variables, check out the Lua manual - specifically the sections explaining require, package.path, and package.cpath.

The bin folder

The meat and potatoes of this project are the wrapper scripts bin/env and bin/luarocks, which automatically set LUA_PATH and LUA_CPATH to use the project-supplied modules before system modules.

bin/env

This script automatically prepends project directories to the environment variables LUA_PATH and LUA_CPATH before executing all arguments after as a separate command. For example: bin/env lua51 -e "print(package.path)" will print the project's LUA_PATH value.

You could also run busted and other binaries that rely on LUA_PATH and LUA_CPATH within the environment using bin/env busted. Obviously, if you have installed binaries through LuaRocks in the project, you will need to reference its location in the lua_modules folder.

bin/luarocks

This script calls bin/env automatically and calls /usr/bin/env luarocks --tree "<project_path>/lua_modules>". For example, if you wanted to download all dependencies, use bin/luarocks build --only-deps.

The Rockspec

This project comes with a simple nil-dev-1.rockspec file. Obviously, the filename and contents should be updated to reflect the project and its dependencies. Unfortunately, LuaRocks does not support functionality similar to npm install <package_name> with the --save or --save-dev flags, so the dependencies need to be added by hand.