LuaCov is a simple coverage analyzer for Lua 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
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.
Download and Installation
LuaCov can be downloaded from its Github downloads page.
It can also be installed using Luarocks:
luarocks install luacov
LuaCov is written in pure Lua and has no external dependencies.
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 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
lua -lluacov test.lua
Alternatively, you can add
require("luacov") to the first line of your
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
luacov.report.out. The script take the following parameters;
luacov [-c=configfile] [filename [ filename[ ...]]]
-c option see below at configuration. The filenames (actually
patterns) indicate the files to include in the report, specifying them here
equals to adding them to the
include list in the configuration file.
This is an example output of the report file:
============================================================ ../test.lua ============================================================ -- Which branch will run? 1 if 10 > 100 then 0 print("I don't think this line will execute.") 0 else 1 print("Hello, LuaCov!") 1 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
module ran (the stats file stores the filenames, but not the sources
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, which periodically saves the stats file. For example, to
run (on Unix systems) LuaCov on
Xavante, just modify the first line of
xavante_start.lua so it reads:
#!/usr/bin/env lua -lluacov.tick
LuaCov includes several configuration options, which have their defaults
/luacov/defaults.lua. These are the global defaults. To create
project specific defaults, copy the file and store it as
.luacov in the
project directory from where
luacov is being run.
Options include changing filenames, automatic report generation upon completion and removal of the stats after generating the report.
LuaCov was designed and implemented by Hisham Muhammad as a tool for testing LuaRocks.