1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Example KUnit test to show how to use KUnit.
4  *
5  * Copyright (C) 2019, Google LLC.
6  * Author: Brendan Higgins <brendanhiggins@google.com>
7  */
8 
9 #include <kunit/test.h>
10 
11 /*
12  * This is the most fundamental element of KUnit, the test case. A test case
13  * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if
14  * any expectations or assertions are not met, the test fails; otherwise, the
15  * test passes.
16  *
17  * In KUnit, a test case is just a function with the signature
18  * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores
19  * information about the current test.
20  */
21 static void example_simple_test(struct kunit *test)
22 {
23 	/*
24 	 * This is an EXPECTATION; it is how KUnit tests things. When you want
25 	 * to test a piece of code, you set some expectations about what the
26 	 * code should do. KUnit then runs the test and verifies that the code's
27 	 * behavior matched what was expected.
28 	 */
29 	KUNIT_EXPECT_EQ(test, 1 + 1, 2);
30 }
31 
32 /*
33  * This is run once before each test case, see the comment on
34  * example_test_suite for more information.
35  */
36 static int example_test_init(struct kunit *test)
37 {
38 	kunit_info(test, "initializing\n");
39 
40 	return 0;
41 }
42 
43 /*
44  * This test should always be skipped.
45  */
46 static void example_skip_test(struct kunit *test)
47 {
48 	/* This line should run */
49 	kunit_info(test, "You should not see a line below.");
50 
51 	/* Skip (and abort) the test */
52 	kunit_skip(test, "this test should be skipped");
53 
54 	/* This line should not execute */
55 	KUNIT_FAIL(test, "You should not see this line.");
56 }
57 
58 /*
59  * This test should always be marked skipped.
60  */
61 static void example_mark_skipped_test(struct kunit *test)
62 {
63 	/* This line should run */
64 	kunit_info(test, "You should see a line below.");
65 
66 	/* Skip (but do not abort) the test */
67 	kunit_mark_skipped(test, "this test should be skipped");
68 
69 	/* This line should run */
70 	kunit_info(test, "You should see this line.");
71 }
72 /*
73  * Here we make a list of all the test cases we want to add to the test suite
74  * below.
75  */
76 static struct kunit_case example_test_cases[] = {
77 	/*
78 	 * This is a helper to create a test case object from a test case
79 	 * function; its exact function is not important to understand how to
80 	 * use KUnit, just know that this is how you associate test cases with a
81 	 * test suite.
82 	 */
83 	KUNIT_CASE(example_simple_test),
84 	KUNIT_CASE(example_skip_test),
85 	KUNIT_CASE(example_mark_skipped_test),
86 	{}
87 };
88 
89 /*
90  * This defines a suite or grouping of tests.
91  *
92  * Test cases are defined as belonging to the suite by adding them to
93  * `kunit_cases`.
94  *
95  * Often it is desirable to run some function which will set up things which
96  * will be used by every test; this is accomplished with an `init` function
97  * which runs before each test case is invoked. Similarly, an `exit` function
98  * may be specified which runs after every test case and can be used to for
99  * cleanup. For clarity, running tests in a test suite would behave as follows:
100  *
101  * suite.init(test);
102  * suite.test_case[0](test);
103  * suite.exit(test);
104  * suite.init(test);
105  * suite.test_case[1](test);
106  * suite.exit(test);
107  * ...;
108  */
109 static struct kunit_suite example_test_suite = {
110 	.name = "example",
111 	.init = example_test_init,
112 	.test_cases = example_test_cases,
113 };
114 
115 /*
116  * This registers the above test suite telling KUnit that this is a suite of
117  * tests that need to be run.
118  */
119 kunit_test_suites(&example_test_suite);
120 
121 MODULE_LICENSE("GPL v2");
122