Commit fadb08e7c750 ("kunit: Support for Parameterized Testing") introduced support but lacks documentation for how to use it.

This patch builds on commit 1f0e943df68a ("Documentation: kunit: provide guidance for testing many inputs") to show a minimal example of the new feature.

Signed-off-by: Daniel Latypov dlatypov@google.com --- Documentation/dev-tools/kunit/usage.rst | 57 +++++++++++++++++++++++++ 1 file changed, 57 insertions(+)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index d9fdc14f0677..650f99590df5 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -522,6 +522,63 @@ There's more boilerplate involved, but it can: * E.g. if we wanted to also test ``sha256sum``, we could add a ``sha256`` field and reuse ``cases``.

+* be converted to a "parameterized test", see below. + +Parameterized Testing +~~~~~~~~~~~~~~~~~~~~~ + +The table-driven testing pattern is common enough that KUnit has special +support for it. + +Reusing the same ``cases`` array from above, we can write the test as a +"parameterized test" with the following. + +.. code-block:: c + + // This is copy-pasted from above. + struct sha1_test_case { + const char *str; + const char *sha1; + }; + struct sha1_test_case cases[] = { + { + .str = "hello world", + .sha1 = "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed", + }, + { + .str = "hello world!", + .sha1 = "430ce34d020724ed75a196dfc2ad67c77772d169", + }, + }; + + // Need a helper function to generate a name for each test case. + static void case_to_desc(const struct sha1_test_case *t, char *desc) + { + strcpy(desc, t->str); + } + // Creates `sha1_gen_params()` to iterate over `cases`. + KUNIT_ARRAY_PARAM(sha1, cases, case_to_desc); + + // Looks no different from a normal test. + static void sha1_test(struct kunit *test) + { + // This function can just contain the body of the for-loop. + // The former `cases[i]` is accessible under test->param_value. + char out[40]; + struct sha1_test_case *test_param = (struct sha1_test_case *)(test->param_value); + + sha1sum(test_param->str, out); + KUNIT_EXPECT_STREQ_MSG(test, (char *)out, test_param->sha1, + "sha1sum(%s)", test_param->str); + } + + // Instead of KUNIT_CASE, we use KUNIT_CASE_PARAM and pass in the + // function declared by KUNIT_ARRAY_PARAM. + static struct kunit_case sha1_test_cases[] = { + KUNIT_CASE_PARAM(sha1_test, sha1_gen_params), + {} + }; + .. _kunit-on-non-uml:

KUnit on non-UML architectures

base-commit: 5f6b99d0287de2c2d0b5e7abcb0092d553ad804a