Commit f9687f35 authored by Marie Zhussupova's avatar Marie Zhussupova Committed by Shuah Khan
Browse files

kunit: Add example parameterized test with direct dynamic parameter array setup 

Introduce example_params_test_with_init_dynamic_arr(). This new
KUnit test demonstrates directly assigning a dynamic parameter
array, using the kunit_register_params_array() macro, to a
parameterized test context.

It highlights the use of param_init() and param_exit() for
initialization and exit of a parameterized test, and their
registration to the test case with KUNIT_CASE_PARAM_WITH_INIT().

Link: https://lore.kernel.org/r/20250826091341.1427123-7-davidgow@google.com


Reviewed-by: default avatarRae Moar <rmoar@google.com>
Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarMarie Zhussupova <marievic@google.com>
Signed-off-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent a03e3caa

lib/kunit/kunit-example-test.c

+104 −0
Original line number Diff line number Diff line
@@ -388,6 +388,107 @@ static void example_params_test_with_init(struct kunit *test) 
	kunit_put_resource(res);

}



/*

 * Helper function to create a parameter array of Fibonacci numbers. This example

 * highlights a parameter generation scenario that is:

 * 1. Not feasible to fully pre-generate at compile time.

 * 2. Challenging to implement with a standard generate_params() function,

 * as it only provides the previous parameter, while Fibonacci requires

 * access to two preceding values for calculation.

 */

static void *make_fibonacci_params(struct kunit *test, size_t seq_size)

{

	int *seq;



	if (seq_size <= 0)

		return NULL;

	/*

	 * Using kunit_kmalloc_array here ties the lifetime of the array to

	 * the parameterized test i.e. it will get automatically cleaned up

	 * by KUnit after the parameterized test finishes.

	 */

	seq = kunit_kmalloc_array(test, seq_size, sizeof(int), GFP_KERNEL);



	if (!seq)

		return NULL;

	if (seq_size >= 1)

		seq[0] = 0;

	if (seq_size >= 2)

		seq[1] = 1;

	for (int i = 2; i < seq_size; i++)

		seq[i] = seq[i - 1] + seq[i - 2];

	return seq;

}



/*

 * This is an example of a function that provides a description for each of the

 * parameters.

 */

static void example_param_dynamic_arr_get_desc(struct kunit *test, const void *p, char *desc)

{

	const int *fib_num = p;



	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "fibonacci param: %d", *fib_num);

}



/*

 * Example of a parameterized test param_init() function that registers a dynamic

 * array of parameters.

 */

static int example_param_init_dynamic_arr(struct kunit *test)

{

	size_t seq_size;

	int *fibonacci_params;



	kunit_info(test, "initializing parameterized test\n");



	seq_size = 6;

	fibonacci_params = make_fibonacci_params(test, seq_size);



	if (!fibonacci_params)

		return -ENOMEM;



	/*

	 * Passes the dynamic parameter array information to the parameterized test

	 * context struct kunit. The array and its metadata will be stored in

	 * test->parent->params_array. The array itself will be located in

	 * params_data.params.

	 *

	 * Note that you will need to pass kunit_array_gen_params() as the

	 * generator function to KUNIT_CASE_PARAM_WITH_INIT() when registering

	 * a parameter array this route.

	 */

	kunit_register_params_array(test, fibonacci_params, seq_size,

				    example_param_dynamic_arr_get_desc);

	return 0;

}



/*

 * Example of a parameterized test param_exit() function that outputs a log

 * at the end of the parameterized test. It could also be used for any other

 * teardown logic.

 */

static void example_param_exit_dynamic_arr(struct kunit *test)

{

	kunit_info(test, "exiting parameterized test\n");

}



/*

 * Example of test that uses the registered dynamic array to perform assertions

 * and expectations.

 */

static void example_params_test_with_init_dynamic_arr(struct kunit *test)

{

	const int *param = test->param_value;

	int param_val;



	/* By design, param pointer will not be NULL. */

	KUNIT_ASSERT_NOT_NULL(test, param);



	param_val = *param;

	KUNIT_EXPECT_EQ(test, param_val - param_val, 0);

}



/*

 * Here we make a list of all the test cases we want to add to the test suite

 * below.
@@ -409,6 +510,9 @@ static struct kunit_case example_test_cases[] = { 
	KUNIT_CASE_PARAM(example_params_test, example_gen_params),

	KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init, kunit_array_gen_params,

				   example_param_init, NULL),

	KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init_dynamic_arr,

				   kunit_array_gen_params, example_param_init_dynamic_arr,

				   example_param_exit_dynamic_arr),

	KUNIT_CASE_SLOW(example_slow_test),

	{}

};