[PATCH v3 6/7] t/README: A new section about test coverage
From: Ævar Arnfjörð Bjarmason <hidden>
Date: 2016-06-15 22:49:11
Subsystem:
the rest · Maintainer:
Linus Torvalds
Document how test writers can generate coverage reports, to ensure that their tests are really testing the code they think they're testing. Signed-off-by: Ævar Arnfjörð Bjarmason <redacted> --- t/README | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 42 insertions(+), 0 deletions(-)
diff --git a/t/README b/t/README
index 0d1183c..15d4b52 100644
--- a/t/README
+++ b/t/README@@ -268,6 +268,9 @@ Do: git push gh && test ... + - Check the test coverage for your tests. See the "Test coverage" + below. + Don't: - exit() within a <script> part.
@@ -508,3 +511,42 @@ the purpose of t0000-basic.sh, which is to isolate that level of validation in one place. Your test also ends up needing updating when such a change to the internal happens, so do _not_ do it and leave the low level of validation to t0000-basic.sh. + +Test coverage +------------- + +You can use the coverage tests to find code paths that are not being +used or properly exercised yet. + +To do that, run the coverage target at the top-level (not in the t/ +directory): + + make coverage + +That'll compile Git with GCC's coverage arguments, and generate a test +report with gcov after the tests finish. Running the coverage tests +can take a while, since running the tests in parallel is incompatible +with GCC's coverage mode. + +After the tests have run you can generate a list of untested +functions: + + make coverage-untested-functions + +You can also generate a detailed per-file HTML report using the +Devel::Cover module. To install it do: + + # On Debian or Ubuntu: + sudo aptitude install libdevel-cover-perl + + # From the CPAN with cpanminus + curl -L http://cpanmin.us | perl - --sudo --self-upgrade + cpanm --sudo Devel::Cover + +Then, at the top-level: + + make cover_db_html + +That'll generate a detailed cover report in the "cover_db_html" +directory, which you can then copy to a webserver, or inspect locally +in a browser.
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1.7.0.4