- Basic usage
- Related projects
- Building and testing
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
sudo if necessary):
luarocks install luacheck
For parallel checking Luacheck additionally requires LuaLanes, which can be installed using LuaRocks as well (
luarocks install lanes).
Windows binary download
After Luacheck is installed, run
luacheck program 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:
- For Vim, Syntastic contains luacheck checker;
- For Sublime Text 3 there is SublimeLinter-luacheck which requires SublimeLinter;
- For Atom there is linter-luacheck which requires AtomLinter;
- For Emacs, Flycheck contains luacheck checker;
- For Brackets, there is linter.luacheck extension;
- For Visual Studio code there is vscode-luacheck extension. vscode-lua extension also includes Luacheck support.
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 luacheck command.
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
luacheck module 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.
Building and testing
After the Luacheck repo is cloned and changes are made, run
luarocks make (using
sudo if 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.