Re: [PATCH v2 2/2] lib/math/rational: Add Kunit test cases

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Tue, May 25, 2021 at 07:42:50AM -0700, Trent Piepho wrote:
> Adds a number of test cases that cover a range of possible code paths.

Good for the starter!
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Trent Piepho <tpiepho@gmail.com>
> ---
>  lib/Kconfig.debug        | 12 +++++++++
>  lib/math/Makefile        |  1 +
>  lib/math/rational-test.c | 56 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 69 insertions(+)
>  create mode 100644 lib/math/rational-test.c
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 678c13967580..6c0e66a7d416 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2429,6 +2429,18 @@ config BITS_TEST
>  
>  	  If unsure, say N.
>  
> +config RATIONAL_KUNIT_TEST
> +	tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
> +	depends on KUNIT
> +	select RATIONAL
> +	default KUNIT_ALL_TESTS
> +	help
> +	  This builds the rational math unit test.
> +	  For more information on KUnit and unit tests in general please refer
> +	  to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> +	  If unsure, say N.
> +
>  config TEST_UDELAY
>  	tristate "udelay test driver"
>  	help
> diff --git a/lib/math/Makefile b/lib/math/Makefile
> index 7456edb864fc..bfac26ddfc22 100644
> --- a/lib/math/Makefile
> +++ b/lib/math/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_PRIME_NUMBERS)	+= prime_numbers.o
>  obj-$(CONFIG_RATIONAL)		+= rational.o
>  
>  obj-$(CONFIG_TEST_DIV64)	+= test_div64.o
> +obj-$(CONFIG_RATIONAL_KUNIT_TEST) += rational-test.o
> diff --git a/lib/math/rational-test.c b/lib/math/rational-test.c
> new file mode 100644
> index 000000000000..f64166dbe9ea
> --- /dev/null
> +++ b/lib/math/rational-test.c
> @@ -0,0 +1,56 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <kunit/test.h>
> +
> +#include <linux/rational.h>
> +
> +struct rational_test_param {
> +	unsigned long num, den;
> +	unsigned long max_num, max_den;
> +	unsigned long exp_num, exp_den;
> +
> +	const char *name;
> +};
> +
> +static const struct rational_test_param test_parameters[] = {
> +	{ 1230,	10,	100, 20,	100, 1,    "Exceeds bounds, semi-convergent term > ½ last term" },
> +	{ 34567,100, 	120, 20,	120, 1,    "Exceeds bounds, semi-convergent term < ½ last term" },
> +	{ 1, 30,	100, 10,	0, 1,	   "Closest to zero" },
> +	{ 1, 19,	100, 10,	1, 10,     "Closest to smallest non-zero" },
> +	{ 27,32,	16, 16,		11, 13,    "Use convergent" },
> +	{ 1155, 7735,	255, 255,	33, 221,   "Exact answer" },
> +	{ 87, 32,	70, 32,		68, 25,    "Semiconvergent, numerator limit" },
> +	{ 14533, 4626,	15000, 2400,	7433, 2366, "Semiconvergent, demominator limit" },
> +};
> +
> +static void get_desc(const struct rational_test_param *param, char *desc)
> +{
> +	strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
> +}
> +
> +/* Creates function rational_gen_params */
> +KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
> +
> +static void rational_test(struct kunit *test)
> +{
> +	const struct rational_test_param *param = (const struct rational_test_param *)test->param_value;
> +	unsigned long n = 0, d = 0;
> +
> +	rational_best_approximation(param->num, param->den, param->max_num, param->max_den, &n, &d);
> +	KUNIT_EXPECT_EQ(test, n, param->exp_num);
> +	KUNIT_EXPECT_EQ(test, d, param->exp_den);
> +}
> +
> +static struct kunit_case rational_test_cases[] = {
> +       KUNIT_CASE_PARAM(rational_test, rational_gen_params),
> +       {}
> +};
> +
> +static struct kunit_suite rational_test_suite = {
> +       .name = "rational",
> +       .test_cases = rational_test_cases,
> +};
> +
> +kunit_test_suites(&rational_test_suite);
> +
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.26.2
> 

-- 
With Best Regards,
Andy Shevchenko