1 .. SPDX-License-Identifier: GPL-2.0
2
3 =================================
4 KUnit - Linux Kernel Unit Testing
5 =================================
6
7 .. toctree::
8 :maxdepth: 2
9 :caption: Contents:
10
11 start
12 architecture
13 run_wrapper
14 run_manual
15 usage
16 api/index
17 style
18 faq
19 running_tips
20
21 This section details the kernel unit testing f
22
23 Introduction
24 ============
25
26 KUnit (Kernel unit testing framework) provides
27 unit tests within the Linux kernel. Using KUni
28 of test cases called test suites. The tests ei
29 if built-in, or load as a module. KUnit automa
30 failed test cases in the kernel log. The test
31 :doc:`KTAP (Kernel - Test Anything Protocol) f
32 It is inspired by JUnit, Python’s unittest.m
33 (C++ unit testing framework).
34
35 KUnit tests are part of the kernel, written in
36 language, and test parts of the Kernel impleme
37 language function). Excluding build time, from
38 completion, KUnit can run around 100 tests in
39 KUnit can test any kernel component, for examp
40 calls, memory management, device drivers and s
41
42 KUnit follows the white-box testing approach.
43 internal system functionality. KUnit runs in k
44 restricted to things exposed to user-space.
45
46 In addition, KUnit has kunit_tool, a script (`
47 that configures the Linux kernel, runs KUnit t
48 (:doc:`User Mode Linux </virt/uml/user_mode_li
49 parses the test results and
50 displays them in a user friendly manner.
51
52 Features
53 --------
54
55 - Provides a framework for writing unit tests.
56 - Runs tests on any kernel architecture.
57 - Runs a test in milliseconds.
58
59 Prerequisites
60 -------------
61
62 - Any Linux kernel compatible hardware.
63 - For Kernel under test, Linux kernel version
64
65 Unit Testing
66 ============
67
68 A unit test tests a single unit of code in iso
69 granularity of testing and allows all possible
70 code under test. This is possible if the code
71 have any external dependencies outside of the
72
73
74 Write Unit Tests
75 ----------------
76
77 To write good unit tests, there is a simple bu
78 Arrange-Act-Assert. This is a great way to str
79 defines an order of operations.
80
81 - Arrange inputs and targets: At the start of
82 that allows a function to work. Example: ini
83 object.
84 - Act on the target behavior: Call your functi
85 - Assert expected outcome: Verify that the res
86 expected.
87
88 Unit Testing Advantages
89 -----------------------
90
91 - Increases testing speed and development in t
92 - Detects bugs at initial stage and therefore
93 compared to acceptance testing.
94 - Improves code quality.
95 - Encourages writing testable code.
96
97 Read also :ref:`kinds-of-tests`.
98
99 How do I use it?
100 ================
101
102 You can find a step-by-step guide to writing a
103 Documentation/dev-tools/kunit/start.rst
104
105 Alternatively, feel free to look through the r
106 or to experiment with tools/testing/kunit/kuni
107 lib/kunit/kunit-example-test.c
108
109 Happy testing!
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