1// SPDX-License-Identifier: GPL-2.0
2
3#include <kunit/test.h>
4
5#include <linux/rational.h>
6
7struct rational_test_param {
8	unsigned long num, den;
9	unsigned long max_num, max_den;
10	unsigned long exp_num, exp_den;
11
12	const char *name;
13};
14
15static const struct rational_test_param test_parameters[] = {
16	{ 1230,	10,	100, 20,	100, 1,    "Exceeds bounds, semi-convergent term > 1/2 last term" },
17	{ 34567,100, 	120, 20,	120, 1,    "Exceeds bounds, semi-convergent term < 1/2 last term" },
18	{ 1, 30,	100, 10,	0, 1,	   "Closest to zero" },
19	{ 1, 19,	100, 10,	1, 10,     "Closest to smallest non-zero" },
20	{ 27,32,	16, 16,		11, 13,    "Use convergent" },
21	{ 1155, 7735,	255, 255,	33, 221,   "Exact answer" },
22	{ 87, 32,	70, 32,		68, 25,    "Semiconvergent, numerator limit" },
23	{ 14533, 4626,	15000, 2400,	7433, 2366, "Semiconvergent, denominator limit" },
24};
25
26static void get_desc(const struct rational_test_param *param, char *desc)
27{
28	strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
29}
30
31/* Creates function rational_gen_params */
32KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
33
34static void rational_test(struct kunit *test)
35{
36	const struct rational_test_param *param = (const struct rational_test_param *)test->param_value;
37	unsigned long n = 0, d = 0;
38
39	rational_best_approximation(param->num, param->den, param->max_num, param->max_den, &n, &d);
40	KUNIT_EXPECT_EQ(test, n, param->exp_num);
41	KUNIT_EXPECT_EQ(test, d, param->exp_den);
42}
43
44static struct kunit_case rational_test_cases[] = {
45	KUNIT_CASE_PARAM(rational_test, rational_gen_params),
46	{}
47};
48
49static struct kunit_suite rational_test_suite = {
50	.name = "rational",
51	.test_cases = rational_test_cases,
52};
53
54kunit_test_suites(&rational_test_suite);
55
56MODULE_LICENSE("GPL v2");
57