## Status
[](https://github.com/lunarmodules/luacov/actions/workflows/unix_build.yml)
[](https://ci.appveyor.com/project/hishamhm/luacov)
[](https://github.com/lunarmodules/luacov/actions/workflows/lint.yml)
[](CHANGELOG.md)
## Overview
LuaCov is a simple coverage analyzer for [Lua](http://www.lua.org) scripts.
When a Lua script is run with the `luacov` module loaded, it generates a stats
file with the number of executions of each line of the script and its loaded
modules. The `luacov` command-line script then processes this file generating
a report file which allows one to visualize which code paths were not
traversed, which is useful for verifying the effectiveness of a test suite.
LuaCov is free software and, like Lua, is released under the
[MIT License](https://www.lua.org/license.html).
## Download and Installation
LuaCov can be downloaded from its
[Github downloads page](https://github.com/lunarmodules/luacov/releases).
It can also be installed using Luarocks:
```
luarocks install luacov
```
In order to additionally install experimental C extensions that improve
performance and analysis accuracy install
[CLuaCov](https://github.com/mpeterv/cluacov) package instead:
```
luarocks install cluacov
```
LuaCov is written in pure Lua and has no external dependencies.
## Instructions
Using LuaCov consists of two steps: running your script to collect coverage
data, and then running `luacov` on the collected data to generate a report
(see [configuration](#configuration) below for other options).
To collect coverage data, your script needs to load the `luacov` Lua module.
This can be done from the command-line, without modifying your script, like
this:
lua -lluacov test.lua
Alternatively, you can add `require("luacov")` to the first line of your
script.
Once the script is run, a file called `luacov.stats.out` is generated. If the
file already exists, statistics are _added_ to it. This is useful, for
example, for making a series of runs with different input parameters in a test
suite. To start the accounting from scratch, just delete the stats file.
To generate a report, just run the `luacov` command-line script. It expects to
find a file named `luacov.stats.out` in the current directory, and outputs a
file named `luacov.report.out`. The script takes the following parameters:
luacov [-c=configfile] [filename...]
For the `-c` option see below at [configuration](#configuration). The filenames
(actually Lua patterns) indicate the files to include in the report, specifying
them here equals to adding them to the `include` list in the configuration
file, with `.lua` extension stripped.
This is an example output of the report file:
```
==============================================================================
test.lua
==============================================================================
1 if 10 > 100 then
*0 print("I don't think this line will execute.")
else
1 print("Hello, LuaCov!")
end
```
Note that to generate this report, `luacov` reads the source files. Therefore,
it expects to find them in the same location they were when the `luacov`
module ran (the stats file stores the filenames, but not the sources
themselves).
To silence missed line reporting for a group of lines, place inline options
`luacov: disable` and `luacov: enable` in short comments around them:
```lua
if SOME_DEBUG_CONDITION_THAT_IS_ALWAYS_FALSE_IN_TESTS then
-- luacov: disable
-- Lines here are not marked as missed even though they are not covered.
-- luacov: enable
end
```
LuaCov saves its stats upon normal program termination. If your program is a
daemon -- in other words, if it does not terminate normally -- you can use the
`luacov.tick` module or `tick` configuration option, which periodically saves
the stats file. For example, to run (on Unix systems) LuaCov on
[Xavante](httpsf://lunarmodules.github.io/xavante/), just modify the first line
of `xavante_start.lua` so it reads:
```
#!/usr/bin/env lua -lluacov.tick
```
or add
```lua
tick = true
```
to `.luacov` config file.
## Configuration
LuaCov includes several configuration options, which have their defaults
stored in `src/luacov/defaults.lua`. These are the global defaults. To use
project specific configuration, create a Lua script setting options as globals
or returning a table with some options and store it as `.luacov` in the project
directory from where `luacov` is being run. Alternatively, store it elsewhere
and specify the path in the `LUACOV_CONFIG` environment variable.
For example, this config informs LuaCov that only `foo` module and its
submodules should be covered and that they are located inside `src` directory:
```lua
modules = {
["foo"] = "src/foo/init.lua",
["foo.*"] = "src"
}
```
For a full list of options, see
[`luacov.defaults` documentation](https://lunarmodules.github.io/luacov/doc/modules/luacov.defaults.html).
## Html reporter
To generate report file as html document, adjust the `.luacov` parameters to
```lua
reporter = "html"
reportfile = "luacov.report.html"
```
## Custom reporter engines
LuaCov supports custom reporter engines, which are distributed as separate
packages. Check them out!
* Cobertura: https://github.com/britzl/luacov-cobertura
* Coveralls: https://github.com/moteus/luacov-coveralls
* Console: https://github.com/spacewander/luacov-console
* LCOV: https://github.com/daurnimator/luacov-reporter-lcov
## Using development version
After cloning this repo, these commands may be useful:
* `luarocks make` to install LuaCov from local sources;
* `busted` to run tests using [busted](https://github.com/Olivine-Labs/busted).
* `ldoc .` to regenerate documentation using
[LDoc](https://github.com/stevedonovan/LDoc).
* `luacheck .` to lint using [Luacheck](https://github.com/lunarmodules/luacheck).
## Credits
LuaCov was designed and implemented by Hisham Muhammad as a tool for testing
[LuaRocks](https://luarocks.org/).
