When writing a test suite for a program or library, it is desirable to know what
part of the code is covered by the test suite. The
coverage) module provides tools to gather code coverage data and to present
them, as detailed below.
Run thunk, a zero-argument procedure, using vm; instrument vm to collect code coverage data. Return code coverage data and the values returned by thunk.
#t if obj is a coverage data object as returned by
Traverse code coverage information data, as obtained with
with-code-coverage, and write coverage information to port in the
.info format used by LCOV. The report will include all of modules (or, by default, all the
currently loaded modules) even if their code was not executed.
The generated data can be fed to LCOV’s
genhtml command to produce an
HTML report, which aids coverage data visualization.
Here’s an example use:
(use-modules (system vm coverage) (system vm vm)) (call-with-values (lambda () (with-code-coverage (the-vm) (lambda () (do-something-tricky)))) (lambda (data result) (let ((port (open-output-file "lcov.info"))) (coverage-data->lcov data port) (close file))))
In addition, the module provides low-level procedures that would make it possible to write other user interfaces to the coverage data.
Return the list of “instrumented” source files, i.e., source files whose code was loaded at the time data was collected.
Return a list of line number/execution count pairs for file, or
#f if file is not among the files covered by data. This
includes lines with zero count.
Return the number of instrumented and the number of executed source lines in file according to data.
Return the number of times proc’s code was executed, according to
#f if proc was not executed. When proc
is a closure, the number of times its code was executed is returned, not
the number of times this code associated with this particular closure was