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 #include <kunit/static_stub.h> 11 12 /* 13 * This is the most fundamental element of KUnit, the test case. A test case 14 * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if 15 * any expectations or assertions are not met, the test fails; otherwise, the 16 * test passes. 17 * 18 * In KUnit, a test case is just a function with the signature 19 * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores 20 * information about the current test. 21 */ 22 static void example_simple_test(struct kunit *test) 23 { 24 /* 25 * This is an EXPECTATION; it is how KUnit tests things. When you want 26 * to test a piece of code, you set some expectations about what the 27 * code should do. KUnit then runs the test and verifies that the code's 28 * behavior matched what was expected. 29 */ 30 KUNIT_EXPECT_EQ(test, 1 + 1, 2); 31 } 32 33 /* 34 * This is run once before each test case, see the comment on 35 * example_test_suite for more information. 36 */ 37 static int example_test_init(struct kunit *test) 38 { 39 kunit_info(test, "initializing\n"); 40 41 return 0; 42 } 43 44 /* 45 * This is run once before all test cases in the suite. 46 * See the comment on example_test_suite for more information. 47 */ 48 static int example_test_init_suite(struct kunit_suite *suite) 49 { 50 kunit_info(suite, "initializing suite\n"); 51 52 return 0; 53 } 54 55 /* 56 * This test should always be skipped. 57 */ 58 static void example_skip_test(struct kunit *test) 59 { 60 /* This line should run */ 61 kunit_info(test, "You should not see a line below."); 62 63 /* Skip (and abort) the test */ 64 kunit_skip(test, "this test should be skipped"); 65 66 /* This line should not execute */ 67 KUNIT_FAIL(test, "You should not see this line."); 68 } 69 70 /* 71 * This test should always be marked skipped. 72 */ 73 static void example_mark_skipped_test(struct kunit *test) 74 { 75 /* This line should run */ 76 kunit_info(test, "You should see a line below."); 77 78 /* Skip (but do not abort) the test */ 79 kunit_mark_skipped(test, "this test should be skipped"); 80 81 /* This line should run */ 82 kunit_info(test, "You should see this line."); 83 } 84 85 /* 86 * This test shows off all the types of KUNIT_EXPECT macros. 87 */ 88 static void example_all_expect_macros_test(struct kunit *test) 89 { 90 const u32 array1[] = { 0x0F, 0xFF }; 91 const u32 array2[] = { 0x1F, 0xFF }; 92 93 /* Boolean assertions */ 94 KUNIT_EXPECT_TRUE(test, true); 95 KUNIT_EXPECT_FALSE(test, false); 96 97 /* Integer assertions */ 98 KUNIT_EXPECT_EQ(test, 1, 1); /* check == */ 99 KUNIT_EXPECT_GE(test, 1, 1); /* check >= */ 100 KUNIT_EXPECT_LE(test, 1, 1); /* check <= */ 101 KUNIT_EXPECT_NE(test, 1, 0); /* check != */ 102 KUNIT_EXPECT_GT(test, 1, 0); /* check > */ 103 KUNIT_EXPECT_LT(test, 0, 1); /* check < */ 104 105 /* Pointer assertions */ 106 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, test); 107 KUNIT_EXPECT_PTR_EQ(test, NULL, NULL); 108 KUNIT_EXPECT_PTR_NE(test, test, NULL); 109 KUNIT_EXPECT_NULL(test, NULL); 110 KUNIT_EXPECT_NOT_NULL(test, test); 111 112 /* String assertions */ 113 KUNIT_EXPECT_STREQ(test, "hi", "hi"); 114 KUNIT_EXPECT_STRNEQ(test, "hi", "bye"); 115 116 /* Memory block assertions */ 117 KUNIT_EXPECT_MEMEQ(test, array1, array1, sizeof(array1)); 118 KUNIT_EXPECT_MEMNEQ(test, array1, array2, sizeof(array1)); 119 120 /* 121 * There are also ASSERT variants of all of the above that abort test 122 * execution if they fail. Useful for memory allocations, etc. 123 */ 124 KUNIT_ASSERT_GT(test, sizeof(char), 0); 125 126 /* 127 * There are also _MSG variants of all of the above that let you include 128 * additional text on failure. 129 */ 130 KUNIT_EXPECT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!"); 131 KUNIT_ASSERT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!"); 132 } 133 134 /* This is a function we'll replace with static stubs. */ 135 static int add_one(int i) 136 { 137 /* This will trigger the stub if active. */ 138 KUNIT_STATIC_STUB_REDIRECT(add_one, i); 139 140 return i + 1; 141 } 142 143 /* This is used as a replacement for the above function. */ 144 static int subtract_one(int i) 145 { 146 /* We don't need to trigger the stub from the replacement. */ 147 148 return i - 1; 149 } 150 151 /* 152 * This test shows the use of static stubs. 153 */ 154 static void example_static_stub_test(struct kunit *test) 155 { 156 /* By default, function is not stubbed. */ 157 KUNIT_EXPECT_EQ(test, add_one(1), 2); 158 159 /* Replace add_one() with subtract_one(). */ 160 kunit_activate_static_stub(test, add_one, subtract_one); 161 162 /* add_one() is now replaced. */ 163 KUNIT_EXPECT_EQ(test, add_one(1), 0); 164 165 /* Return add_one() to normal. */ 166 kunit_deactivate_static_stub(test, add_one); 167 KUNIT_EXPECT_EQ(test, add_one(1), 2); 168 } 169 170 /* 171 * Here we make a list of all the test cases we want to add to the test suite 172 * below. 173 */ 174 static struct kunit_case example_test_cases[] = { 175 /* 176 * This is a helper to create a test case object from a test case 177 * function; its exact function is not important to understand how to 178 * use KUnit, just know that this is how you associate test cases with a 179 * test suite. 180 */ 181 KUNIT_CASE(example_simple_test), 182 KUNIT_CASE(example_skip_test), 183 KUNIT_CASE(example_mark_skipped_test), 184 KUNIT_CASE(example_all_expect_macros_test), 185 KUNIT_CASE(example_static_stub_test), 186 {} 187 }; 188 189 /* 190 * This defines a suite or grouping of tests. 191 * 192 * Test cases are defined as belonging to the suite by adding them to 193 * `kunit_cases`. 194 * 195 * Often it is desirable to run some function which will set up things which 196 * will be used by every test; this is accomplished with an `init` function 197 * which runs before each test case is invoked. Similarly, an `exit` function 198 * may be specified which runs after every test case and can be used to for 199 * cleanup. For clarity, running tests in a test suite would behave as follows: 200 * 201 * suite.suite_init(suite); 202 * suite.init(test); 203 * suite.test_case[0](test); 204 * suite.exit(test); 205 * suite.init(test); 206 * suite.test_case[1](test); 207 * suite.exit(test); 208 * suite.suite_exit(suite); 209 * ...; 210 */ 211 static struct kunit_suite example_test_suite = { 212 .name = "example", 213 .init = example_test_init, 214 .suite_init = example_test_init_suite, 215 .test_cases = example_test_cases, 216 }; 217 218 /* 219 * This registers the above test suite telling KUnit that this is a suite of 220 * tests that need to be run. 221 */ 222 kunit_test_suites(&example_test_suite); 223 224 MODULE_LICENSE("GPL v2"); 225