Linux kernel mirror (for testing)
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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 */
21static 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 */
36static 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 */
46static 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 */
61static 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/*
74 * This test shows off all the types of KUNIT_EXPECT macros.
75 */
76static void example_all_expect_macros_test(struct kunit *test)
77{
78 /* Boolean assertions */
79 KUNIT_EXPECT_TRUE(test, true);
80 KUNIT_EXPECT_FALSE(test, false);
81
82 /* Integer assertions */
83 KUNIT_EXPECT_EQ(test, 1, 1); /* check == */
84 KUNIT_EXPECT_GE(test, 1, 1); /* check >= */
85 KUNIT_EXPECT_LE(test, 1, 1); /* check <= */
86 KUNIT_EXPECT_NE(test, 1, 0); /* check != */
87 KUNIT_EXPECT_GT(test, 1, 0); /* check > */
88 KUNIT_EXPECT_LT(test, 0, 1); /* check < */
89
90 /* Pointer assertions */
91 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, test);
92 KUNIT_EXPECT_PTR_EQ(test, NULL, NULL);
93 KUNIT_EXPECT_PTR_NE(test, test, NULL);
94
95 /* String assertions */
96 KUNIT_EXPECT_STREQ(test, "hi", "hi");
97 KUNIT_EXPECT_STRNEQ(test, "hi", "bye");
98
99 /*
100 * There are also ASSERT variants of all of the above that abort test
101 * execution if they fail. Useful for memory allocations, etc.
102 */
103 KUNIT_ASSERT_GT(test, sizeof(char), 0);
104
105 /*
106 * There are also _MSG variants of all of the above that let you include
107 * additional text on failure.
108 */
109 KUNIT_EXPECT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!");
110 KUNIT_ASSERT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!");
111}
112
113/*
114 * Here we make a list of all the test cases we want to add to the test suite
115 * below.
116 */
117static struct kunit_case example_test_cases[] = {
118 /*
119 * This is a helper to create a test case object from a test case
120 * function; its exact function is not important to understand how to
121 * use KUnit, just know that this is how you associate test cases with a
122 * test suite.
123 */
124 KUNIT_CASE(example_simple_test),
125 KUNIT_CASE(example_skip_test),
126 KUNIT_CASE(example_mark_skipped_test),
127 KUNIT_CASE(example_all_expect_macros_test),
128 {}
129};
130
131/*
132 * This defines a suite or grouping of tests.
133 *
134 * Test cases are defined as belonging to the suite by adding them to
135 * `kunit_cases`.
136 *
137 * Often it is desirable to run some function which will set up things which
138 * will be used by every test; this is accomplished with an `init` function
139 * which runs before each test case is invoked. Similarly, an `exit` function
140 * may be specified which runs after every test case and can be used to for
141 * cleanup. For clarity, running tests in a test suite would behave as follows:
142 *
143 * suite.init(test);
144 * suite.test_case[0](test);
145 * suite.exit(test);
146 * suite.init(test);
147 * suite.test_case[1](test);
148 * suite.exit(test);
149 * ...;
150 */
151static struct kunit_suite example_test_suite = {
152 .name = "example",
153 .init = example_test_init,
154 .test_cases = example_test_cases,
155};
156
157/*
158 * This registers the above test suite telling KUnit that this is a suite of
159 * tests that need to be run.
160 */
161kunit_test_suites(&example_test_suite);
162
163MODULE_LICENSE("GPL v2");