Re: [PATCH v1 14/17] Documentation: kunit: add documentation for KUnit

Add documentation for KUnit, the Linux kernel unit testing framework. - Add intro and usage guide for KUnit - Add API reference Signed-off-by: Felix Guo <felixguoxiuping(a)gmail.com&gt; Signed-off-by: Brendan Higgins <brendanhiggins(a)google.com&gt; ---

diff --git a/Documentation/kunit/start.rst b/Documentation/kunit/start.rst new file mode 100644 index 0000000000000..5cdba5091905e --- /dev/null +++ b/Documentation/kunit/start.rst

+Assertions +~~~~~~~~~~ + +KUnit also has the concept of an *assertion*. An assertion is just like an +expectation except the assertion immediately terminates the test case if it is +not satisfied. + +For example: + +.. code-block:: c + + static void mock_test_do_expect_default_return(struct kunit *test) + { + struct mock_test_context *ctx = test->priv; + struct mock *mock = ctx->mock; + int param0 = 5, param1 = -5; + const char *two_param_types[] = {"int", "int"}; + const void *two_params[] = {&param0, &param1}; + const void *ret; + + ret = mock->do_expect(mock, + "test_printk", test_printk, + two_param_types, two_params, + ARRAY_SIZE(two_params));

+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);

+ KUNIT_EXPECT_EQ(test, -4, *((int *) ret)); + } + +In this example, the method under test should return a pointer to a value, so +if the pointer returned by the method is null or an errno, we don't want to +bother continuing the test since the following expectation could crash the test

+case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us to bail out of the test case if