"gcov — a Test Coverage Program"
"lcov — a graphical frontend for gcov"
"Coverage.py is a tool for measuring code coverage of Python programs."
"OpenClover — Java, Groovy and AspectJ code coverage tool"
"Coveralls — Test Coverage History & Statistics"
"undercover.el: A test coverage library for Emacs"
cov
shows code coverage data for your program in emacs. Currently,
it supports gcov
, lcov
, coverage.py
, and clover
output, as well as the Coveralls
format produced by
undercover.el
.
cov
is on MELPA. To install it, type M-x package-install RET cov RET
Enable cov-mode
in a buffer. It will use the methods in
cov-coverage-file-paths
to look for a suitable coverage data file.
cov-mode
uses file watchers to automatically reload the coverage
file when it has been updated.
Line coverage is displayed in the left fringe and added to the
help-echo
text property of the line.
By default, cov
will run in profiling mode. Lines which are executed
a lot will have the fringe decorated with cov-heavy-face
, while
lines executed less will have the fringe decorated with cov-med-face
and cov-light-face
. Lines not executed at all will be decorated with
cov-none-face
.
Use the cov-high-threshold
and cov-med-threshold
variables to
customize where the limits between haevy, medium, and light execution
should be.
Setting cov-coverage-mode
to t
before enabling cov-mode
will
run cov in coverage mode. In this mode lines will be marked with
cov-coverage-run-face
or cov-coverage-not-run-face
to executed and
non-executed lines respectively. Coverage mode should make finding
uncovered lines slightly easier than profiling mode.
Coverage files are located using the methods in
cov-coverage-file-paths
, a list of paths or functions that are tried
in order to find a matching coverage file for the current buffer.
Paths can be used for coverage files which have the same name as the
source file but with a suffix added, like gcov
. So far gcov
is
the only supported tool that uses this scheme, but more can be added
by appending to cov-coverage-alist
. cov-coverage-alist
bind
postfixes to the coverage tools:
(setq cov-coverage-alist '((".gcov" . gcov)))
For other tool or more complex environments it is also possible to provide a
function instead of a path string. The function will be called with
the path and name of the buffer file and should return a cons cell of
the form (COV-FILE-PATH . COVERAGE-TOOL)
. PATH
shall be the full path
and name of the coverage data file. COVERAGE-TOOL
shall specify the
coverage tool.
gcov
files are located using cov-coverage-file-paths
as described
above.
An lcov
tracefile can contain data for multiple source files and can
be named anything. There are two ways to find tracefiles.
Set cov-lcov-file-name
to the absolute path of the tracefile.
This can be done with a directory- or file-local variable.
Add pattarns or functions to cov-lcov-patterns
.
Relative or absolute file patterns like "../lcov.info" will be
tested in order to find a matching file. Functions takes the dir
and name of the source file as arguments and should return an
absolute path.
Coveralls file are named coverage-final.json
and are searched for in
each directory from the source file to the root.
Clover file are named clover.xml
and are searched for in
each directory from the source file to the root.
coverage.py
file are named coverage.json
and are searched for in
each directory from the source file to the root.
cov.el
can be extended to understand more coverage formats. To add
a new format:
cov-coverage-file-paths
that locates a coverage
file for a given file. If a coverage file is found, it should
return a cons of the coverage file path and an identifier, like
(cons filepath 'mytool)
. The original name of the file can be
found in the cov-coverage-file
buffer local variable.cov--mytool-parse
. The parse function is called with
a temp buffer with the coverage file data as (current-buffer)
and
should parse the data and return the coverage as a alist of files
to coverage mapping. Coverage data is simply a list of two element
lists, where the first element is the line number and the second
the coverage count.Install dependencies:
cask install
Run tests:
cask exec ert-runner
GPLv3+