Re: [PATCH v2 1/2] unicode: kunit: refactor selftest to kunit tests

[Gabriel Krisman Bertazi <gabriel@krisman.be>]

Pedro Orlando <porlando@lkcamp.dev> writes:

> From: Gabriela Bittencourt <gbittencourt@lkcamp.dev>
>
> Refactoring 'test' functions into kunit tests, to test utf-8 support in
> unicode subsystem.
>
> This allows the utf8 tests to be run alongside the KUnit test suite
> using kunit-tool, quickly compiling and running all desired tests as
> part of the KUnit test suite, instead of compiling the selftest module
> and loading it.
>
> The refactoring kept the original testing logic intact, while adopting a
> testing pattern across different kernel modules and leveraging KUnit's
> benefits.
>
> Co-developed-by: Pedro Orlando <porlando@lkcamp.dev>
> Signed-off-by: Pedro Orlando <porlando@lkcamp.dev>
> Co-developed-by: Danilo Pereira <dpereira@lkcamp.dev>
> Signed-off-by: Danilo Pereira <dpereira@lkcamp.dev>
> Signed-off-by: Gabriela Bittencourt <gbittencourt@lkcamp.dev>
> ---
>
> About the KUNIT readability, there are two ways of obtaing the results:
> 1- using `_TRUE(test, func == ret)` which may make the code more
> readable, but the error message less informative. For example:
> `false, but expect true`; unless we use _TRUE_MSG(test, cond, msg) to
> customize the error message (which is what we've done here).
> 2- using `_EQ(test, func, ret)` which may be a little less readable, but the
> default error message will carry more information. For example:
> `64, but expected 0`
>
> ---
>  fs/unicode/.kunitconfig    |   3 +
>  fs/unicode/Kconfig         |   5 +-
>  fs/unicode/Makefile        |   2 +-
>  fs/unicode/utf8-selftest.c | 149 +++++++++++++++++--------------------
>  4 files changed, 76 insertions(+), 83 deletions(-)
>  create mode 100644 fs/unicode/.kunitconfig
>
> diff --git a/fs/unicode/.kunitconfig b/fs/unicode/.kunitconfig
> new file mode 100644
> index 000000000000..62dd5c171f9c
> --- /dev/null
> +++ b/fs/unicode/.kunitconfig
> @@ -0,0 +1,3 @@
> +CONFIG_KUNIT=y
> +CONFIG_UNICODE=y
> +CONFIG_UNICODE_NORMALIZATION_KUNIT_TEST=y
> diff --git a/fs/unicode/Kconfig b/fs/unicode/Kconfig
> index da786a687fdc..4ad2c36550f1 100644
> --- a/fs/unicode/Kconfig
> +++ b/fs/unicode/Kconfig
> @@ -10,6 +10,7 @@ config UNICODE
>  	  be a separate loadable module that gets requested only when a file
>  	  system actually use it.
>  
> -config UNICODE_NORMALIZATION_SELFTEST
> +config UNICODE_NORMALIZATION_KUNIT_TEST

This rename is missing a spot at the bottom of utf8norm.c:

#ifdef CONFIG_UNICODE_NORMALIZATION_SELFTEST_MODULE
EXPORT_SYMBOL_GPL(utf8version_is_supported);
EXPORT_SYMBOL_GPL(utf8nlen);
EXPORT_SYMBOL_GPL(utf8ncursor);
EXPORT_SYMBOL_GPL(utf8byte);
#endif

Which is needed when UNICODE_NORMALIZATION_KUNIT_TEST=m.

>  	tristate "Test UTF-8 normalization support"
> -	depends on UNICODE
> +	depends on UNICODE && KUNIT
> +	default KUNIT_ALL_TESTS
> diff --git a/fs/unicode/Makefile b/fs/unicode/Makefile
> index e309afe2b2bb..37bbcbc628a1 100644
> --- a/fs/unicode/Makefile
> +++ b/fs/unicode/Makefile
> @@ -4,7 +4,7 @@ ifneq ($(CONFIG_UNICODE),)
>  obj-y			+= unicode.o
>  endif
>  obj-$(CONFIG_UNICODE)	+= utf8data.o
> -obj-$(CONFIG_UNICODE_NORMALIZATION_SELFTEST) += utf8-selftest.o
> +obj-$(CONFIG_UNICODE_NORMALIZATION_KUNIT_TEST) += utf8-selftest.o
>  
>  unicode-y := utf8-norm.o utf8-core.o
>  
> diff --git a/fs/unicode/utf8-selftest.c b/fs/unicode/utf8-selftest.c
> index 600e15efe9ed..52ab68ef2bbc 100644
> --- a/fs/unicode/utf8-selftest.c
> +++ b/fs/unicode/utf8-selftest.c
> @@ -1,38 +1,18 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /*
> - * Kernel module for testing utf-8 support.
> + * KUnit tests for utf-8 support.
>   *
>   * Copyright 2017 Collabora Ltd.
>   */
>  
> -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> -
> -#include <linux/module.h>
> -#include <linux/printk.h>
>  #include <linux/unicode.h>
> -#include <linux/dcache.h>
> +#include <kunit/test.h>
>  
>  #include "utf8n.h"
>  
> -static unsigned int failed_tests;
> -static unsigned int total_tests;
> -
>  /* Tests will be based on this version. */
>  #define UTF8_LATEST	UNICODE_AGE(12, 1, 0)
>  
> -#define _test(cond, func, line, fmt, ...) do {				\
> -		total_tests++;						\
> -		if (!cond) {						\
> -			failed_tests++;					\
> -			pr_err("test %s:%d Failed: %s%s",		\
> -			       func, line, #cond, (fmt?":":"."));	\
> -			if (fmt)					\
> -				pr_err(fmt, ##__VA_ARGS__);		\
> -		}							\
> -	} while (0)
> -#define test_f(cond, fmt, ...) _test(cond, __func__, __LINE__, fmt, ##__VA_ARGS__)
> -#define test(cond) _test(cond, __func__, __LINE__, "")
> -
>  static const struct {
>  	/* UTF-8 strings in this vector _must_ be NULL-terminated. */
>  	unsigned char str[10];
> @@ -170,69 +150,74 @@ static int utf8cursor(struct utf8cursor *u8c, const struct unicode_map *um,
>  	return utf8ncursor(u8c, um, n, s, (unsigned int)-1);
>  }
>  
> -static void check_utf8_nfdi(struct unicode_map *um)
> +static void check_utf8_nfdi(struct kunit *test)
>  {
>  	int i;
>  	struct utf8cursor u8c;
> +	struct unicode_map *um = test->priv;
>  
>  	for (i = 0; i < ARRAY_SIZE(nfdi_test_data); i++) {
>  		int len = strlen(nfdi_test_data[i].str);
>  		int nlen = strlen(nfdi_test_data[i].dec);
>  		int j = 0;
>  		unsigned char c;
> +		int ret;
>  
> -		test((utf8len(um, UTF8_NFDI, nfdi_test_data[i].str) == nlen));
> -		test((utf8nlen(um, UTF8_NFDI, nfdi_test_data[i].str, len) ==
> -			nlen));
> +		KUNIT_EXPECT_EQ(test, utf8len(um, UTF8_NFDI, nfdi_test_data[i].str), nlen);
> +		KUNIT_EXPECT_EQ(test, utf8nlen(um, UTF8_NFDI, nfdi_test_data[i].str, len),
> +				nlen);
>  
> -		if (utf8cursor(&u8c, um, UTF8_NFDI, nfdi_test_data[i].str) < 0)
> -			pr_err("can't create cursor\n");
> +
> +		ret = utf8cursor(&u8c, um, UTF8_NFDI, nfdi_test_data[i].str);
> +		KUNIT_EXPECT_TRUE_MSG(test, ret >= 0, "Can't create cursor\n");
>  
>  		while ((c = utf8byte(&u8c)) > 0) {
> -			test_f((c == nfdi_test_data[i].dec[j]),
> -			       "Unexpected byte 0x%x should be 0x%x\n",
> -			       c, nfdi_test_data[i].dec[j]);
> +			KUNIT_EXPECT_EQ_MSG(test, c, nfdi_test_data[i].dec[j],
> +					    "Unexpected byte 0x%x should be 0x%x\n",
> +					    c, nfdi_test_data[i].dec[j]);
>  			j++;
>  		}
>  
> -		test((j == nlen));
> +		KUNIT_EXPECT_EQ(test, j, nlen);
>  	}
>  }
>  
> -static void check_utf8_nfdicf(struct unicode_map *um)
> +static void check_utf8_nfdicf(struct kunit *test)
>  {
>  	int i;
>  	struct utf8cursor u8c;
> +	struct unicode_map *um = test->priv;
>  
>  	for (i = 0; i < ARRAY_SIZE(nfdicf_test_data); i++) {
>  		int len = strlen(nfdicf_test_data[i].str);
>  		int nlen = strlen(nfdicf_test_data[i].ncf);
>  		int j = 0;
> +		int ret;
>  		unsigned char c;
>  
> -		test((utf8len(um, UTF8_NFDICF, nfdicf_test_data[i].str) ==
> -				nlen));
> -		test((utf8nlen(um, UTF8_NFDICF, nfdicf_test_data[i].str, len) ==
> -				nlen));
> +		KUNIT_EXPECT_EQ(test, utf8len(um, UTF8_NFDICF, nfdicf_test_data[i].str),
> +				nlen);
> +		KUNIT_EXPECT_EQ(test, utf8nlen(um, UTF8_NFDICF, nfdicf_test_data[i].str, len),
> +				nlen);
>  
> -		if (utf8cursor(&u8c, um, UTF8_NFDICF,
> -				nfdicf_test_data[i].str) < 0)
> -			pr_err("can't create cursor\n");
> +		ret = utf8cursor(&u8c, um, UTF8_NFDICF, nfdicf_test_data[i].str);
> +		KUNIT_EXPECT_TRUE_MSG(test, ret >= 0, "Can't create cursor\n");
>  
>  		while ((c = utf8byte(&u8c)) > 0) {
> -			test_f((c == nfdicf_test_data[i].ncf[j]),
> -			       "Unexpected byte 0x%x should be 0x%x\n",
> -			       c, nfdicf_test_data[i].ncf[j]);
> +			KUNIT_EXPECT_EQ_MSG(test, c, nfdicf_test_data[i].ncf[j],
> +					    "Unexpected byte 0x%x should be 0x%x\n",
> +					    c, nfdicf_test_data[i].ncf[j]);
>  			j++;
>  		}
>  
> -		test((j == nlen));
> +		KUNIT_EXPECT_EQ(test, j, nlen);
>  	}
>  }
>  
> -static void check_utf8_comparisons(struct unicode_map *table)
> +static void check_utf8_comparisons(struct kunit *test)
>  {
>  	int i;
> +	struct unicode_map *um = test->priv;
>  
>  	for (i = 0; i < ARRAY_SIZE(nfdi_test_data); i++) {
>  		const struct qstr s1 = {.name = nfdi_test_data[i].str,
> @@ -240,8 +225,9 @@ static void check_utf8_comparisons(struct unicode_map *table)
>  		const struct qstr s2 = {.name = nfdi_test_data[i].dec,
>  					.len = sizeof(nfdi_test_data[i].dec)};
>  
> -		test_f(!utf8_strncmp(table, &s1, &s2),
> -		       "%s %s comparison mismatch\n", s1.name, s2.name);
> +		/* strncmp returns 0 when strings are equal */
> +		KUNIT_EXPECT_TRUE_MSG(test, utf8_strncmp(um, &s1, &s2) == 0,
> +				    "%s %s comparison mismatch\n", s1.name, s2.name);
>  	}
>  
>  	for (i = 0; i < ARRAY_SIZE(nfdicf_test_data); i++) {
> @@ -250,62 +236,65 @@ static void check_utf8_comparisons(struct unicode_map *table)
>  		const struct qstr s2 = {.name = nfdicf_test_data[i].ncf,
>  					.len = sizeof(nfdicf_test_data[i].ncf)};
>  
> -		test_f(!utf8_strncasecmp(table, &s1, &s2),
> -		       "%s %s comparison mismatch\n", s1.name, s2.name);
> +		/* strncasecmp returns 0 when strings are equal */
> +		KUNIT_EXPECT_TRUE_MSG(test, utf8_strncasecmp(um, &s1, &s2) == 0,
> +				    "%s %s comparison mismatch\n", s1.name, s2.name);
>  	}
>  }
>  
> -static void check_supported_versions(struct unicode_map *um)
> +static void check_supported_versions(struct kunit *test)
>  {
> +	struct unicode_map *um = test->priv;
>  	/* Unicode 7.0.0 should be supported. */
> -	test(utf8version_is_supported(um, UNICODE_AGE(7, 0, 0)));
> +	KUNIT_EXPECT_TRUE(test, utf8version_is_supported(um, UNICODE_AGE(7, 0, 0)));
>  
>  	/* Unicode 9.0.0 should be supported. */
> -	test(utf8version_is_supported(um, UNICODE_AGE(9, 0, 0)));
> +	KUNIT_EXPECT_TRUE(test, utf8version_is_supported(um, UNICODE_AGE(9, 0, 0)));
>  
>  	/* Unicode 1x.0.0 (the latest version) should be supported. */
> -	test(utf8version_is_supported(um, UTF8_LATEST));
> +	KUNIT_EXPECT_TRUE(test, utf8version_is_supported(um, UTF8_LATEST));
>  
>  	/* Next versions don't exist. */
> -	test(!utf8version_is_supported(um, UNICODE_AGE(13, 0, 0)));
> -	test(!utf8version_is_supported(um, UNICODE_AGE(0, 0, 0)));
> -	test(!utf8version_is_supported(um, UNICODE_AGE(-1, -1, -1)));
> +	KUNIT_EXPECT_FALSE(test, utf8version_is_supported(um, UNICODE_AGE(13, 0, 0)));
> +	KUNIT_EXPECT_FALSE(test, utf8version_is_supported(um, UNICODE_AGE(0, 0, 0)));
> +	KUNIT_EXPECT_FALSE(test, utf8version_is_supported(um, UNICODE_AGE(-1, -1, -1)));
>  }
>  
> -static int __init init_test_ucd(void)
> +static struct kunit_case unicode_normalization_test_cases[] = {
> +	KUNIT_CASE(check_supported_versions),
> +	KUNIT_CASE(check_utf8_comparisons),
> +	KUNIT_CASE(check_utf8_nfdicf),
> +	KUNIT_CASE(check_utf8_nfdi),
> +	{}
> +};
> +
> +static int init_test_ucd(struct kunit *test)
>  {
> -	struct unicode_map *um;
> +	struct unicode_map *um = utf8_load(UTF8_LATEST);
>  
> -	failed_tests = 0;
> -	total_tests = 0;
> +	test->priv = um;
>  
> -	um = utf8_load(UTF8_LATEST);
> -	if (IS_ERR(um)) {
> -		pr_err("%s: Unable to load utf8 table.\n", __func__);
> -		return PTR_ERR(um);
> -	}
> +	KUNIT_EXPECT_EQ_MSG(test, IS_ERR(um), 0,
> +			    "%s: Unable to load utf8 table.\n", __func__);
>  
> -	check_supported_versions(um);
> -	check_utf8_nfdi(um);
> -	check_utf8_nfdicf(um);
> -	check_utf8_comparisons(um);
> -
> -	if (!failed_tests)
> -		pr_info("All %u tests passed\n", total_tests);
> -	else
> -		pr_err("%u out of %u tests failed\n", failed_tests,
> -		       total_tests);
> -	utf8_unload(um);
>  	return 0;
>  }
>  
> -static void __exit exit_test_ucd(void)
> +static void exit_test_ucd(struct kunit *test)
>  {
> +	utf8_unload(test->priv);
>  }
>  
> -module_init(init_test_ucd);
> -module_exit(exit_test_ucd);
> +static struct kunit_suite unicode_normalization_test_suite = {
> +	.name = "unicode_normalization",
> +	.test_cases = unicode_normalization_test_cases,
> +	.init = init_test_ucd,
> +	.exit = exit_test_ucd,
> +};
> +
> +kunit_test_suite(unicode_normalization_test_suite);
> +
>  
>  MODULE_AUTHOR("Gabriel Krisman Bertazi <krisman@collabora.co.uk>");
> -MODULE_DESCRIPTION("Kernel module for testing utf-8 support");
> +MODULE_DESCRIPTION("KUnit tests for utf-8 support.");
>  MODULE_LICENSE("GPL");

-- 
Gabriel Krisman Bertazi