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| 1.. SPDX-License-Identifier: GPL-2.0 2 3Writing Tests 4============= 5 6Test Cases 7---------- 8 --- 783 unchanged lines hidden (view full) --- 792 #else 793 static void my_debug_function(void) { } 794 #endif 795 796``kunit_fail_current_test()`` is safe to call even if KUnit is not enabled. If 797KUnit is not enabled, or if no test is running in the current task, it will do 798nothing. This compiles down to either a no-op or a static key check, so will 799have a negligible performance impact when no test is running. | 1.. SPDX-License-Identifier: GPL-2.0 2 3Writing Tests 4============= 5 6Test Cases 7---------- 8 --- 783 unchanged lines hidden (view full) --- 792 #else 793 static void my_debug_function(void) { } 794 #endif 795 796``kunit_fail_current_test()`` is safe to call even if KUnit is not enabled. If 797KUnit is not enabled, or if no test is running in the current task, it will do 798nothing. This compiles down to either a no-op or a static key check, so will 799have a negligible performance impact when no test is running. |
| 800 801Managing Fake Devices and Drivers 802--------------------------------- 803 804When testing drivers or code which interacts with drivers, many functions will 805require a ``struct device`` or ``struct device_driver``. In many cases, setting 806up a real device is not required to test any given function, so a fake device 807can be used instead. 808 809KUnit provides helper functions to create and manage these fake devices, which 810are internally of type ``struct kunit_device``, and are attached to a special 811``kunit_bus``. These devices support managed device resources (devres), as 812described in Documentation/driver-api/driver-model/devres.rst 813 814To create a KUnit-managed ``struct device_driver``, use ``kunit_driver_create()``, 815which will create a driver with the given name, on the ``kunit_bus``. This driver 816will automatically be destroyed when the corresponding test finishes, but can also 817be manually destroyed with ``driver_unregister()``. 818 819To create a fake device, use the ``kunit_device_register()``, which will create 820and register a device, using a new KUnit-managed driver created with ``kunit_driver_create()``. 821To provide a specific, non-KUnit-managed driver, use ``kunit_device_register_with_driver()`` 822instead. Like with managed drivers, KUnit-managed fake devices are automatically 823cleaned up when the test finishes, but can be manually cleaned up early with 824``kunit_device_unregister()``. 825 826The KUnit devices should be used in preference to ``root_device_register()``, and 827instead of ``platform_device_register()`` in cases where the device is not otherwise 828a platform device. 829 830For example: 831 832.. code-block:: c 833 834 #include <kunit/device.h> 835 836 static void test_my_device(struct kunit *test) 837 { 838 struct device *fake_device; 839 const char *dev_managed_string; 840 841 // Create a fake device. 842 fake_device = kunit_device_register(test, "my_device"); 843 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_device) 844 845 // Pass it to functions which need a device. 846 dev_managed_string = devm_kstrdup(fake_device, "Hello, World!"); 847 848 // Everything is cleaned up automatically when the test ends. 849 } |
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