2022-11-09 01:06:16

by Daniel Latypov

[permalink] [raw]
Subject: [PATCH v2 1/3] Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication

usage.rst had most of the content of the tips.rst page copied over.
But it's missing https://www.kernel.org/doc/html/v6.0/dev-tools/kunit/tips.html#customizing-error-messages
Copy it over so we can retire tips.rst w/o losing content.

And in that process, it also gained a duplicate section about how
KUNIT_ASSERT_*() exit the test case early. Remove that.

Signed-off-by: Daniel Latypov <[email protected]>
---
Documentation/dev-tools/kunit/usage.rst | 49 ++++++++++++++++---------
1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index 2737863ef365..b0a6c3bc0eeb 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -118,6 +118,37 @@ expectation could crash the test case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us
to bail out of the test case if the appropriate conditions are not satisfied to
complete the test.

+Customizing error messages
+--------------------------
+
+Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG``
+variant. These take a format string and arguments to provide additional
+context to the automatically generated error messages.
+
+.. code-block:: c
+
+ char some_str[41];
+ generate_sha1_hex_string(some_str);
+
+ /* Before. Not easy to tell why the test failed. */
+ KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
+
+ /* After. Now we see the offending string. */
+ KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
+
+Alternatively, one can take full control over the error message by using
+``KUNIT_FAIL()``, e.g.
+
+.. code-block:: c
+
+ /* Before */
+ KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
+
+ /* After: full control over the failure message. */
+ if (some_setup_function())
+ KUNIT_FAIL(test, "Failed to setup thing for testing");
+
+
Test Suites
~~~~~~~~~~~

@@ -546,24 +577,6 @@ By reusing the same ``cases`` array from above, we can write the test as a
{}
};

-Exiting Early on Failed Expectations
-------------------------------------
-
-We can use ``KUNIT_EXPECT_EQ`` to mark the test as failed and continue
-execution. In some cases, it is unsafe to continue. We can use the
-``KUNIT_ASSERT`` variant to exit on failure.
-
-.. code-block:: c
-
- void example_test_user_alloc_function(struct kunit *test)
- {
- void *object = alloc_some_object_for_me();
-
- /* Make sure we got a valid pointer back. */
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
- do_something_with_object(object);
- }
-
Allocating Memory
-----------------


base-commit: 6fe1ad4a156095859721fef85073df3ed43081d4
--
2.38.1.431.g37b22c650d-goog



2022-11-09 01:12:59

by Daniel Latypov

[permalink] [raw]
Subject: [PATCH v2 3/3] Documentation: kunit: Remove redundant 'tips.rst' page

From: David Gow <[email protected]>

The contents of 'tips.rst' was mostly included in 'usage.rst' way back in
commit 953574390634 ("Documentation: KUnit: Rework writing page to focus on writing tests"),
but the tips page remained behind as well.

The parent patches in this series fill in the gaps, so now 'tips.rst' is
redundant.
Therefore, delete 'tips.rst'.

While I regret breaking any links to 'tips' which might exist
externally, it's confusing to have two subtly different versions of the
same content around.

Signed-off-by: David Gow <[email protected]>
Signed-off-by: Daniel Latypov <[email protected]>
---
v1 -> v2: rebased onto some parent patches to fix the missing sections
in usage.rst and tweaked the commit message to reflect that.
---
Documentation/dev-tools/kunit/index.rst | 1 -
Documentation/dev-tools/kunit/tips.rst | 190 ------------------------
2 files changed, 191 deletions(-)
delete mode 100644 Documentation/dev-tools/kunit/tips.rst

diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
index f5d13f1d37be..d5629817cd72 100644
--- a/Documentation/dev-tools/kunit/index.rst
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -16,7 +16,6 @@ KUnit - Linux Kernel Unit Testing
api/index
style
faq
- tips
running_tips

This section details the kernel unit testing framework.
diff --git a/Documentation/dev-tools/kunit/tips.rst b/Documentation/dev-tools/kunit/tips.rst
deleted file mode 100644
index 492d2ded2f5a..000000000000
--- a/Documentation/dev-tools/kunit/tips.rst
+++ /dev/null
@@ -1,190 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-============================
-Tips For Writing KUnit Tests
-============================
-
-Exiting early on failed expectations
-------------------------------------
-
-``KUNIT_EXPECT_EQ`` and friends will mark the test as failed and continue
-execution. In some cases, it's unsafe to continue and you can use the
-``KUNIT_ASSERT`` variant to exit on failure.
-
-.. code-block:: c
-
- void example_test_user_alloc_function(struct kunit *test)
- {
- void *object = alloc_some_object_for_me();
-
- /* Make sure we got a valid pointer back. */
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
- do_something_with_object(object);
- }
-
-Allocating memory
------------------
-
-Where you would use ``kzalloc``, you should prefer ``kunit_kzalloc`` instead.
-KUnit will ensure the memory is freed once the test completes.
-
-This is particularly useful since it lets you use the ``KUNIT_ASSERT_EQ``
-macros to exit early from a test without having to worry about remembering to
-call ``kfree``.
-
-Example:
-
-.. code-block:: c
-
- void example_test_allocation(struct kunit *test)
- {
- char *buffer = kunit_kzalloc(test, 16, GFP_KERNEL);
- /* Ensure allocation succeeded. */
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
-
- KUNIT_ASSERT_STREQ(test, buffer, "");
- }
-
-
-Testing static functions
-------------------------
-
-If you don't want to expose functions or variables just for testing, one option
-is to conditionally ``#include`` the test file at the end of your .c file, e.g.
-
-.. code-block:: c
-
- /* In my_file.c */
-
- static int do_interesting_thing();
-
- #ifdef CONFIG_MY_KUNIT_TEST
- #include "my_kunit_test.c"
- #endif
-
-Injecting test-only code
-------------------------
-
-Similarly to the above, it can be useful to add test-specific logic.
-
-.. code-block:: c
-
- /* In my_file.h */
-
- #ifdef CONFIG_MY_KUNIT_TEST
- /* Defined in my_kunit_test.c */
- void test_only_hook(void);
- #else
- void test_only_hook(void) { }
- #endif
-
-This test-only code can be made more useful by accessing the current kunit
-test, see below.
-
-Accessing the current test
---------------------------
-
-In some cases, you need to call test-only code from outside the test file, e.g.
-like in the example above or if you're providing a fake implementation of an
-ops struct.
-There is a ``kunit_test`` field in ``task_struct``, so you can access it via
-``current->kunit_test``.
-
-Here's a slightly in-depth example of how one could implement "mocking":
-
-.. code-block:: c
-
- #include <linux/sched.h> /* for current */
-
- struct test_data {
- int foo_result;
- int want_foo_called_with;
- };
-
- static int fake_foo(int arg)
- {
- struct kunit *test = current->kunit_test;
- struct test_data *test_data = test->priv;
-
- KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg);
- return test_data->foo_result;
- }
-
- static void example_simple_test(struct kunit *test)
- {
- /* Assume priv is allocated in the suite's .init */
- struct test_data *test_data = test->priv;
-
- test_data->foo_result = 42;
- test_data->want_foo_called_with = 1;
-
- /* In a real test, we'd probably pass a pointer to fake_foo somewhere
- * like an ops struct, etc. instead of calling it directly. */
- KUNIT_EXPECT_EQ(test, fake_foo(1), 42);
- }
-
-
-Note: here we're able to get away with using ``test->priv``, but if you wanted
-something more flexible you could use a named ``kunit_resource``, see
-Documentation/dev-tools/kunit/api/test.rst.
-
-Failing the current test
-------------------------
-
-But sometimes, you might just want to fail the current test. In that case, we
-have ``kunit_fail_current_test(fmt, args...)`` which is defined in ``<kunit/test-bug.h>`` and
-doesn't require pulling in ``<kunit/test.h>``.
-
-E.g. say we had an option to enable some extra debug checks on some data structure:
-
-.. code-block:: c
-
- #include <kunit/test-bug.h>
-
- #ifdef CONFIG_EXTRA_DEBUG_CHECKS
- static void validate_my_data(struct data *data)
- {
- if (is_valid(data))
- return;
-
- kunit_fail_current_test("data %p is invalid", data);
-
- /* Normal, non-KUnit, error reporting code here. */
- }
- #else
- static void my_debug_function(void) { }
- #endif
-
-
-Customizing error messages
---------------------------
-
-Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG`` variant.
-These take a format string and arguments to provide additional context to the automatically generated error messages.
-
-.. code-block:: c
-
- char some_str[41];
- generate_sha1_hex_string(some_str);
-
- /* Before. Not easy to tell why the test failed. */
- KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
-
- /* After. Now we see the offending string. */
- KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
-
-Alternatively, one can take full control over the error message by using ``KUNIT_FAIL()``, e.g.
-
-.. code-block:: c
-
- /* Before */
- KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
-
- /* After: full control over the failure message. */
- if (some_setup_function())
- KUNIT_FAIL(test, "Failed to setup thing for testing");
-
-Next Steps
-==========
-* Optional: see the Documentation/dev-tools/kunit/usage.rst page for a more
- in-depth explanation of KUnit.
--
2.38.1.431.g37b22c650d-goog


2022-11-10 05:25:19

by Sadiya Kazi

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication

On Wed, Nov 9, 2022 at 6:06 AM 'Daniel Latypov' via KUnit Development
<[email protected]> wrote:
>
> usage.rst had most of the content of the tips.rst page copied over.
> But it's missing https://www.kernel.org/doc/html/v6.0/dev-tools/kunit/tips.html#customizing-error-messages
> Copy it over so we can retire tips.rst w/o losing content.
>
> And in that process, it also gained a duplicate section about how
> KUNIT_ASSERT_*() exit the test case early. Remove that.
>
> Signed-off-by: Daniel Latypov <[email protected]>
> ---

Thanks Daniel. This looks fine to me.
Reviewed-by: Sadiya Kazi <[email protected]>

Best Regards,
Sadiya

> Documentation/dev-tools/kunit/usage.rst | 49 ++++++++++++++++---------
> 1 file changed, 31 insertions(+), 18 deletions(-)
>
> diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
> index 2737863ef365..b0a6c3bc0eeb 100644
> --- a/Documentation/dev-tools/kunit/usage.rst
> +++ b/Documentation/dev-tools/kunit/usage.rst
> @@ -118,6 +118,37 @@ expectation could crash the test case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us
> to bail out of the test case if the appropriate conditions are not satisfied to
> complete the test.
>
> +Customizing error messages
> +--------------------------
> +
> +Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG``
> +variant. These take a format string and arguments to provide additional
> +context to the automatically generated error messages.
> +
> +.. code-block:: c
> +
> + char some_str[41];
> + generate_sha1_hex_string(some_str);
> +
> + /* Before. Not easy to tell why the test failed. */
> + KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
> +
> + /* After. Now we see the offending string. */
> + KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
> +
> +Alternatively, one can take full control over the error message by using
> +``KUNIT_FAIL()``, e.g.
> +
> +.. code-block:: c
> +
> + /* Before */
> + KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
> +
> + /* After: full control over the failure message. */
> + if (some_setup_function())
> + KUNIT_FAIL(test, "Failed to setup thing for testing");
> +
> +
> Test Suites
> ~~~~~~~~~~~
>
> @@ -546,24 +577,6 @@ By reusing the same ``cases`` array from above, we can write the test as a
> {}
> };
>
> -Exiting Early on Failed Expectations
> -------------------------------------
> -
> -We can use ``KUNIT_EXPECT_EQ`` to mark the test as failed and continue
> -execution. In some cases, it is unsafe to continue. We can use the
> -``KUNIT_ASSERT`` variant to exit on failure.
> -
> -.. code-block:: c
> -
> - void example_test_user_alloc_function(struct kunit *test)
> - {
> - void *object = alloc_some_object_for_me();
> -
> - /* Make sure we got a valid pointer back. */
> - KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
> - do_something_with_object(object);
> - }
> -
> Allocating Memory
> -----------------
>
>
> base-commit: 6fe1ad4a156095859721fef85073df3ed43081d4
> --
> 2.38.1.431.g37b22c650d-goog
>
> --
> You received this message because you are subscribed to the Google Groups "KUnit Development" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To view this discussion on the web visit https://groups.google.com/d/msgid/kunit-dev/20221109003618.3784591-1-dlatypov%40google.com.

2022-11-11 06:00:59

by Sadiya Kazi

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] Documentation: kunit: Remove redundant 'tips.rst' page

On Wed, Nov 9, 2022 at 6:06 AM 'Daniel Latypov' via KUnit Development
<[email protected]> wrote:
>
> From: David Gow <[email protected]>
>
> The contents of 'tips.rst' was mostly included in 'usage.rst' way back in
> commit 953574390634 ("Documentation: KUnit: Rework writing page to focus on writing tests"),
> but the tips page remained behind as well.
>
> The parent patches in this series fill in the gaps, so now 'tips.rst' is
> redundant.
> Therefore, delete 'tips.rst'.
>
> While I regret breaking any links to 'tips' which might exist
> externally, it's confusing to have two subtly different versions of the
> same content around.
>
> Signed-off-by: David Gow <[email protected]>
> Signed-off-by: Daniel Latypov <[email protected]>
> ---
> v1 -> v2: rebased onto some parent patches to fix the missing sections
> in usage.rst and tweaked the commit message to reflect that.
> ---

Thank you. This looks fine to me.
Reviewed-by: Sadiya Kazi <[email protected]>


> Documentation/dev-tools/kunit/index.rst | 1 -
> Documentation/dev-tools/kunit/tips.rst | 190 ------------------------
> 2 files changed, 191 deletions(-)
> delete mode 100644 Documentation/dev-tools/kunit/tips.rst
>
> diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
> index f5d13f1d37be..d5629817cd72 100644
> --- a/Documentation/dev-tools/kunit/index.rst
> +++ b/Documentation/dev-tools/kunit/index.rst
> @@ -16,7 +16,6 @@ KUnit - Linux Kernel Unit Testing
> api/index
> style
> faq
> - tips
> running_tips
>
> This section details the kernel unit testing framework.
> diff --git a/Documentation/dev-tools/kunit/tips.rst b/Documentation/dev-tools/kunit/tips.rst
> deleted file mode 100644
> index 492d2ded2f5a..000000000000
> --- a/Documentation/dev-tools/kunit/tips.rst
> +++ /dev/null
> @@ -1,190 +0,0 @@
> -.. SPDX-License-Identifier: GPL-2.0
> -
> -============================
> -Tips For Writing KUnit Tests
> -============================
> -
> -Exiting early on failed expectations
> -------------------------------------
> -
> -``KUNIT_EXPECT_EQ`` and friends will mark the test as failed and continue
> -execution. In some cases, it's unsafe to continue and you can use the
> -``KUNIT_ASSERT`` variant to exit on failure.
> -
> -.. code-block:: c
> -
> - void example_test_user_alloc_function(struct kunit *test)
> - {
> - void *object = alloc_some_object_for_me();
> -
> - /* Make sure we got a valid pointer back. */
> - KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
> - do_something_with_object(object);
> - }
> -
> -Allocating memory
> ------------------
> -
> -Where you would use ``kzalloc``, you should prefer ``kunit_kzalloc`` instead.
> -KUnit will ensure the memory is freed once the test completes.
> -
> -This is particularly useful since it lets you use the ``KUNIT_ASSERT_EQ``
> -macros to exit early from a test without having to worry about remembering to
> -call ``kfree``.
> -
> -Example:
> -
> -.. code-block:: c
> -
> - void example_test_allocation(struct kunit *test)
> - {
> - char *buffer = kunit_kzalloc(test, 16, GFP_KERNEL);
> - /* Ensure allocation succeeded. */
> - KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
> -
> - KUNIT_ASSERT_STREQ(test, buffer, "");
> - }
> -
> -
> -Testing static functions
> -------------------------
> -
> -If you don't want to expose functions or variables just for testing, one option
> -is to conditionally ``#include`` the test file at the end of your .c file, e.g.
> -
> -.. code-block:: c
> -
> - /* In my_file.c */
> -
> - static int do_interesting_thing();
> -
> - #ifdef CONFIG_MY_KUNIT_TEST
> - #include "my_kunit_test.c"
> - #endif
> -
> -Injecting test-only code
> -------------------------
> -
> -Similarly to the above, it can be useful to add test-specific logic.
> -
> -.. code-block:: c
> -
> - /* In my_file.h */
> -
> - #ifdef CONFIG_MY_KUNIT_TEST
> - /* Defined in my_kunit_test.c */
> - void test_only_hook(void);
> - #else
> - void test_only_hook(void) { }
> - #endif
> -
> -This test-only code can be made more useful by accessing the current kunit
> -test, see below.
> -
> -Accessing the current test
> ---------------------------
> -
> -In some cases, you need to call test-only code from outside the test file, e.g.
> -like in the example above or if you're providing a fake implementation of an
> -ops struct.
> -There is a ``kunit_test`` field in ``task_struct``, so you can access it via
> -``current->kunit_test``.
> -
> -Here's a slightly in-depth example of how one could implement "mocking":
> -
> -.. code-block:: c
> -
> - #include <linux/sched.h> /* for current */
> -
> - struct test_data {
> - int foo_result;
> - int want_foo_called_with;
> - };
> -
> - static int fake_foo(int arg)
> - {
> - struct kunit *test = current->kunit_test;
> - struct test_data *test_data = test->priv;
> -
> - KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg);
> - return test_data->foo_result;
> - }
> -
> - static void example_simple_test(struct kunit *test)
> - {
> - /* Assume priv is allocated in the suite's .init */
> - struct test_data *test_data = test->priv;
> -
> - test_data->foo_result = 42;
> - test_data->want_foo_called_with = 1;
> -
> - /* In a real test, we'd probably pass a pointer to fake_foo somewhere
> - * like an ops struct, etc. instead of calling it directly. */
> - KUNIT_EXPECT_EQ(test, fake_foo(1), 42);
> - }
> -
> -
> -Note: here we're able to get away with using ``test->priv``, but if you wanted
> -something more flexible you could use a named ``kunit_resource``, see
> -Documentation/dev-tools/kunit/api/test.rst.
> -
> -Failing the current test
> -------------------------
> -
> -But sometimes, you might just want to fail the current test. In that case, we
> -have ``kunit_fail_current_test(fmt, args...)`` which is defined in ``<kunit/test-bug.h>`` and
> -doesn't require pulling in ``<kunit/test.h>``.
> -
> -E.g. say we had an option to enable some extra debug checks on some data structure:
> -
> -.. code-block:: c
> -
> - #include <kunit/test-bug.h>
> -
> - #ifdef CONFIG_EXTRA_DEBUG_CHECKS
> - static void validate_my_data(struct data *data)
> - {
> - if (is_valid(data))
> - return;
> -
> - kunit_fail_current_test("data %p is invalid", data);
> -
> - /* Normal, non-KUnit, error reporting code here. */
> - }
> - #else
> - static void my_debug_function(void) { }
> - #endif
> -
> -
> -Customizing error messages
> ---------------------------
> -
> -Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG`` variant.
> -These take a format string and arguments to provide additional context to the automatically generated error messages.
> -
> -.. code-block:: c
> -
> - char some_str[41];
> - generate_sha1_hex_string(some_str);
> -
> - /* Before. Not easy to tell why the test failed. */
> - KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
> -
> - /* After. Now we see the offending string. */
> - KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
> -
> -Alternatively, one can take full control over the error message by using ``KUNIT_FAIL()``, e.g.
> -
> -.. code-block:: c
> -
> - /* Before */
> - KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
> -
> - /* After: full control over the failure message. */
> - if (some_setup_function())
> - KUNIT_FAIL(test, "Failed to setup thing for testing");
> -
> -Next Steps
> -==========
> -* Optional: see the Documentation/dev-tools/kunit/usage.rst page for a more
> - in-depth explanation of KUnit.
> --
> 2.38.1.431.g37b22c650d-goog
>
> --
> You received this message because you are subscribed to the Google Groups "KUnit Development" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To view this discussion on the web visit https://groups.google.com/d/msgid/kunit-dev/20221109003618.3784591-3-dlatypov%40google.com.