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 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.
Download and Installation
LuaCov can be downloaded from its LuaForge 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.
To collect coverage data, your script needs to load the
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
lcov.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
lcov.stats.out in the current
directory, and outputs a file named
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
luacov module ran (the stats file stores the filenames, but
not the sources themselves).
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
just modify the first line of
xavante_start.lua so it reads:
#!/usr/bin/env lua -lluacov.tick
LuaCov was designed and implemented by Hisham Muhammad as a tool for testing Luarocks.