1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <kunit/test.h>
4
5 #include <linux/rational.h>
6
7 struct 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
15 static 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
get_desc(const struct rational_test_param * param,char * desc)26 static 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 */
32 KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
33
rational_test(struct kunit * test)34 static 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
44 static struct kunit_case rational_test_cases[] = {
45 KUNIT_CASE_PARAM(rational_test, rational_gen_params),
46 {}
47 };
48
49 static struct kunit_suite rational_test_suite = {
50 .name = "rational",
51 .test_cases = rational_test_cases,
52 };
53
54 kunit_test_suites(&rational_test_suite);
55
56 MODULE_DESCRIPTION("Rational fractions unit test");
57 MODULE_LICENSE("GPL v2");
58