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 /*
74  * This test shows off all the types of KUNIT_EXPECT macros.
75  */
76 static 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  */
117 static 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  */
151 static 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  */
161 kunit_test_suites(&example_test_suite);
162 
163 MODULE_LICENSE("GPL v2");
164