A tool for linting and static analysis of Lua code.
Luacheck is a static analyzer and a linter for Lua. Luacheck detects various issues such as usage of undefined global variables, unused variables and values, accessing uninitialized variables, unreachable code and more. Most aspects of checking are configurable: there are options for defining custom project-related globals, for selecting set of standard globals (version of Lua standard library), for filtering warnings by type and name of related variable, etc. The options can be used on the command line, put into a config or directly into checked files as Lua comments.
Luacheck supports checking Lua files using syntax of Lua 5.1, Lua 5.2, Lua 5.3 and LuaJIT. Luacheck itself is written in Lua and runs on all of mentioned Lua versions.
From your command line run the following command (using
luarocks install luacheck
For parallel checking Luacheck additionally requires LuaLanes, which can be installed using LuaRocks as well (
luarocks install lanes).
After Luacheck is installed, run
luacheckprogram from the command line. Pass a list of files, rockspecs or directories (requires LuaFileSystem) to be checked:
luacheck src extra_file.lua another_file.lua
Checking src/good_code.lua OK Checking src/bad_code.lua 3 warnings
src/bad_code.lua:3:23: unused variable length argument src/bad_code.lua:7:10: setting non-standard global variable embrace src/bad_code.lua:8:10: variable opt was previously defined as an argument on line 7
Checking src/python_code.lua 1 error
src/python_code.lua:1:6: expected '=' near '__future__'
Checking extra_file.lua 5 warnings
extra_file.lua:3:18: unused argument baz extra_file.lua:4:8: unused loop variable i extra_file.lua:13:7: accessing uninitialized variable a extra_file.lua:14:1: value assigned to variable x is unused extra_file.lua:21:7: variable z is never accessed
Checking another_file.lua 2 warnings
another_file.lua:2:7: unused variable height another_file.lua:3:7: accessing undefined variable heigth
Total: 10 warnings / 1 error in 5 files
For more info, see documentation.
There are a few plugins which allow using Luacheck directly inside an editor, showing warnings inline:
If you are a plugin developer, see recommended way of using Luacheck in a plugin.
Documentation is available online. If Luacheck has been installed using LuaRocks, it can be browsed offline using
luarocks doc luacheckcommand.
Documentation can be built using Sphinx:
sphinx-build docsrc doc, the files will be found inside
Luacheck is currently in development. The latest released version is 0.23.0. The interface of the
luacheckmodule may change between minor releases. The command line interface is fairly stable.
Use the Luacheck issue tracker on GitHub to submit bugs, suggestions and questions. Any pull requests are welcome, too.
After the Luacheck repo is cloned and changes are made, run
sudoif necessary) from its root directory to install dev version of Luacheck. To run Luacheck using sources in current directory without installing it, run
lua -e 'package.path="./src/?.lua;./src/?/init.lua;"..package.path' bin/luacheck.lua .... To test Luacheck, ensure that you have busted and luautf8 installed and run
The MIT License (MIT)
Copyright (c) 2014 - 2018 Peter Melnichenko
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.