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

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

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");