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Diffstat (limited to 'Documentation/dev-tools/kunit/style.rst')
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1 files changed, 51 insertions, 54 deletions
diff --git a/Documentation/dev-tools/kunit/style.rst b/Documentation/dev-tools/kunit/style.rst index 8dbcdc552606..b6d0d7359f00 100644 --- a/Documentation/dev-tools/kunit/style.rst +++ b/Documentation/dev-tools/kunit/style.rst @@ -4,37 +4,36 @@ Test Style and Nomenclature =========================== -To make finding, writing, and using KUnit tests as simple as possible, it's +To make finding, writing, and using KUnit tests as simple as possible, it is strongly encouraged that they are named and written according to the guidelines -below. While it's possible to write KUnit tests which do not follow these rules, +below. While it is possible to write KUnit tests which do not follow these rules, they may break some tooling, may conflict with other tests, and may not be run automatically by testing systems. -It's recommended that you only deviate from these guidelines when: +It is recommended that you only deviate from these guidelines when: -1. Porting tests to KUnit which are already known with an existing name, or -2. Writing tests which would cause serious problems if automatically run (e.g., - non-deterministically producing false positives or negatives, or taking an - extremely long time to run). +1. Porting tests to KUnit which are already known with an existing name. +2. Writing tests which would cause serious problems if automatically run. For + example, non-deterministically producing false positives or negatives, or + taking a long time to run. Subsystems, Suites, and Tests ============================= -In order to make tests as easy to find as possible, they're grouped into suites -and subsystems. A test suite is a group of tests which test a related area of -the kernel, and a subsystem is a set of test suites which test different parts -of the same kernel subsystem or driver. +To make tests easy to find, they are grouped into suites and subsystems. A test +suite is a group of tests which test a related area of the kernel. A subsystem +is a set of test suites which test different parts of a kernel subsystem +or a driver. Subsystems ---------- Every test suite must belong to a subsystem. A subsystem is a collection of one or more KUnit test suites which test the same driver or part of the kernel. A -rule of thumb is that a test subsystem should match a single kernel module. If -the code being tested can't be compiled as a module, in many cases the subsystem -should correspond to a directory in the source tree or an entry in the -MAINTAINERS file. If unsure, follow the conventions set by tests in similar -areas. +test subsystem should match a single kernel module. If the code being tested +cannot be compiled as a module, in many cases the subsystem should correspond to +a directory in the source tree or an entry in the ``MAINTAINERS`` file. If +unsure, follow the conventions set by tests in similar areas. Test subsystems should be named after the code being tested, either after the module (wherever possible), or after the directory or files being tested. Test @@ -42,9 +41,8 @@ subsystems should be named to avoid ambiguity where necessary. If a test subsystem name has multiple components, they should be separated by underscores. *Do not* include "test" or "kunit" directly in the subsystem name -unless you are actually testing other tests or the kunit framework itself. - -Example subsystems could be: +unless we are actually testing other tests or the kunit framework itself. For +example, subsystems could be called: ``ext4`` Matches the module and filesystem name. @@ -56,48 +54,46 @@ Example subsystems could be: Has several components (``snd``, ``hda``, ``codec``, ``hdmi``) separated by underscores. Matches the module name. -Avoid names like these: +Avoid names as shown in examples below: ``linear-ranges`` Names should use underscores, not dashes, to separate words. Prefer ``linear_ranges``. ``qos-kunit-test`` - As well as using underscores, this name should not have "kunit-test" as a - suffix, and ``qos`` is ambiguous as a subsystem name. ``power_qos`` would be a - better name. + This name should use underscores, and not have "kunit-test" as a + suffix. ``qos`` is also ambiguous as a subsystem name, because several parts + of the kernel have a ``qos`` subsystem. ``power_qos`` would be a better name. ``pc_parallel_port`` The corresponding module name is ``parport_pc``, so this subsystem should also be named ``parport_pc``. .. note:: - The KUnit API and tools do not explicitly know about subsystems. They're - simply a way of categorising test suites and naming modules which - provides a simple, consistent way for humans to find and run tests. This - may change in the future, though. + The KUnit API and tools do not explicitly know about subsystems. They are + a way of categorizing test suites and naming modules which provides a + simple, consistent way for humans to find and run tests. This may change + in the future. Suites ------ KUnit tests are grouped into test suites, which cover a specific area of -functionality being tested. Test suites can have shared initialisation and -shutdown code which is run for all tests in the suite. -Not all subsystems will need to be split into multiple test suites (e.g. simple drivers). +functionality being tested. Test suites can have shared initialization and +shutdown code which is run for all tests in the suite. Not all subsystems need +to be split into multiple test suites (for example, simple drivers). Test suites are named after the subsystem they are part of. If a subsystem contains several suites, the specific area under test should be appended to the subsystem name, separated by an underscore. In the event that there are multiple types of test using KUnit within a -subsystem (e.g., both unit tests and integration tests), they should be put into -separate suites, with the type of test as the last element in the suite name. -Unless these tests are actually present, avoid using ``_test``, ``_unittest`` or -similar in the suite name. +subsystem (for example, both unit tests and integration tests), they should be +put into separate suites, with the type of test as the last element in the suite +name. Unless these tests are actually present, avoid using ``_test``, ``_unittest`` +or similar in the suite name. The full test suite name (including the subsystem name) should be specified as the ``.name`` member of the ``kunit_suite`` struct, and forms the base for the -module name (see below). - -Example test suites could include: +module name. For example, test suites could include: ``ext4_inode`` Part of the ``ext4`` subsystem, testing the ``inode`` area. @@ -109,26 +105,27 @@ Example test suites could include: The ``kasan`` subsystem has only one suite, so the suite name is the same as the subsystem name. -Avoid names like: +Avoid names, for example: ``ext4_ext4_inode`` - There's no reason to state the subsystem twice. + There is no reason to state the subsystem twice. ``property_entry`` The suite name is ambiguous without the subsystem name. ``kasan_integration_test`` Because there is only one suite in the ``kasan`` subsystem, the suite should - just be called ``kasan``. There's no need to redundantly add - ``integration_test``. Should a separate test suite with, for example, unit - tests be added, then that suite could be named ``kasan_unittest`` or similar. + just be called as ``kasan``. Do not redundantly add + ``integration_test``. It should be a separate test suite. For example, if the + unit tests are added, then that suite could be named as ``kasan_unittest`` or + similar. Test Cases ---------- Individual tests consist of a single function which tests a constrained -codepath, property, or function. In the test output, individual tests' results -will show up as subtests of the suite's results. +codepath, property, or function. In the test output, an individual test's +results will show up as subtests of the suite's results. -Tests should be named after what they're testing. This is often the name of the +Tests should be named after what they are testing. This is often the name of the function being tested, with a description of the input or codepath being tested. As tests are C functions, they should be named and written in accordance with the kernel coding style. @@ -136,7 +133,7 @@ the kernel coding style. .. note:: As tests are themselves functions, their names cannot conflict with other C identifiers in the kernel. This may require some creative - naming. It's a good idea to make your test functions `static` to avoid + naming. It is a good idea to make your test functions `static` to avoid polluting the global namespace. Example test names include: @@ -162,16 +159,16 @@ This Kconfig entry must: * be named ``CONFIG_<name>_KUNIT_TEST``: where <name> is the name of the test suite. * be listed either alongside the config entries for the driver/subsystem being - tested, or be under [Kernel Hacking]→[Kernel Testing and Coverage] -* depend on ``CONFIG_KUNIT`` + tested, or be under [Kernel Hacking]->[Kernel Testing and Coverage] +* depend on ``CONFIG_KUNIT``. * be visible only if ``CONFIG_KUNIT_ALL_TESTS`` is not enabled. * have a default value of ``CONFIG_KUNIT_ALL_TESTS``. -* have a brief description of KUnit in the help text +* have a brief description of KUnit in the help text. -Unless there's a specific reason not to (e.g. the test is unable to be built as -a module), Kconfig entries for tests should be tristate. +If we are not able to meet above conditions (for example, the test is unable to +be built as a module), Kconfig entries for tests should be tristate. -An example Kconfig entry: +For example, a Kconfig entry might look like: .. code-block:: none @@ -182,8 +179,8 @@ An example Kconfig entry: help This builds unit tests for foo. - For more information on KUnit and unit tests in general, please refer - to the KUnit documentation in Documentation/dev-tools/kunit/. + 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. |