Commit 8db50be2 authored by Daniel Latypov's avatar Daniel Latypov Committed by Shuah Khan
Browse files

Documentation: kunit: include example of a parameterized test 



Commit fadb08e7 ("kunit: Support for Parameterized Testing")
introduced support but lacks documentation for how to use it.

This patch builds on commit 1f0e943d ("Documentation: kunit: provide
guidance for testing many inputs") to show a minimal example of the new
feature.

Signed-off-by: default avatarDaniel Latypov <dlatypov@google.com>
Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Tested-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Acked-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent ebfd4488

Documentation/dev-tools/kunit/usage.rst

+57 −0
Original line number Diff line number Diff line
@@ -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