lib/kunit/kunit-example-test.c

   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  * Here we make a list of all the test cases we want to add to the test suite
  45  * below.
  46  */
  47 static struct kunit_case example_test_cases[] = {
  48         /*
  49          * This is a helper to create a test case object from a test case
  50          * function; its exact function is not important to understand how to
  51          * use KUnit, just know that this is how you associate test cases with a
  52          * test suite.
  53          */
  54         KUNIT_CASE(example_simple_test),
  55         {}
  56 };
  57
  58 /*
  59  * This defines a suite or grouping of tests.
  60  *
  61  * Test cases are defined as belonging to the suite by adding them to
  62  * `kunit_cases`.
  63  *
  64  * Often it is desirable to run some function which will set up things which
  65  * will be used by every test; this is accomplished with an `init` function
  66  * which runs before each test case is invoked. Similarly, an `exit` function
  67  * may be specified which runs after every test case and can be used to for
  68  * cleanup. For clarity, running tests in a test suite would behave as follows:
  69  *
  70  * suite.init(test);
  71  * suite.test_case[0](test);
  72  * suite.exit(test);
  73  * suite.init(test);
  74  * suite.test_case[1](test);
  75  * suite.exit(test);
  76  * ...;
  77  */
  78 static struct kunit_suite example_test_suite = {
  79         .name = "example",
  80         .init = example_test_init,
  81         .test_cases = example_test_cases,
  82 };
  83
  84 /*
  85  * This registers the above test suite telling KUnit that this is a suite of
  86  * tests that need to be run.
  87  */
  88 kunit_test_suites(&example_test_suite);
  89
  90 MODULE_LICENSE("GPL v2");