@@ -11,3 +11,26 @@ menuconfig KUNIT
special hardware when using UML. Can also be used on most other
architectures. For more information, please see
Documentation/dev-tools/kunit/.
+
+if KUNIT
+
+config KUNIT_TEST
+ bool "KUnit test for KUnit"
+ help
+ Enables the unit tests for the KUnit test framework. These tests test
+ the KUnit test framework itself; the tests are both written using
+ KUnit and test KUnit. This option should only be enabled for testing
+ purposes by developers interested in testing that KUnit works as
+ expected.
+
+config KUNIT_EXAMPLE_TEST
+ bool "Example test for KUnit"
+ help
+ Enables an example unit test that illustrates some of the basic
+ features of KUnit. This test only exists to help new users understand
+ what KUnit is and how it is used. Please refer to the example test
+ itself, lib/kunit/example-test.c, for more information. This option
+ is intended for curious hackers who would like to understand how to
+ use KUnit for kernel development.
+
+endif # KUNIT
@@ -1,3 +1,7 @@
obj-$(CONFIG_KUNIT) += test.o \
string-stream.o \
assert.o
+
+obj-$(CONFIG_KUNIT_TEST) += string-stream-test.o
+
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) += example-test.o
new file mode 100644
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Example KUnit test to show how to use KUnit.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/test.h>
+
+/*
+ * This is the most fundamental element of KUnit, the test case. A test case
+ * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if
+ * any expectations or assertions are not met, the test fails; otherwise, the
+ * test passes.
+ *
+ * In KUnit, a test case is just a function with the signature
+ * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores
+ * information about the current test.
+ */
+static void example_simple_test(struct kunit *test)
+{
+ /*
+ * This is an EXPECTATION; it is how KUnit tests things. When you want
+ * to test a piece of code, you set some expectations about what the
+ * code should do. KUnit then runs the test and verifies that the code's
+ * behavior matched what was expected.
+ */
+ KUNIT_EXPECT_EQ(test, 1 + 1, 2);
+}
+
+/*
+ * This is run once before each test case, see the comment on
+ * example_test_suite for more information.
+ */
+static int example_test_init(struct kunit *test)
+{
+ kunit_info(test, "initializing\n");
+
+ return 0;
+}
+
+/*
+ * Here we make a list of all the test cases we want to add to the test suite
+ * below.
+ */
+static struct kunit_case example_test_cases[] = {
+ /*
+ * This is a helper to create a test case object from a test case
+ * function; its exact function is not important to understand how to
+ * use KUnit, just know that this is how you associate test cases with a
+ * test suite.
+ */
+ KUNIT_CASE(example_simple_test),
+ {}
+};
+
+/*
+ * This defines a suite or grouping of tests.
+ *
+ * Test cases are defined as belonging to the suite by adding them to
+ * `kunit_cases`.
+ *
+ * Often it is desirable to run some function which will set up things which
+ * will be used by every test; this is accomplished with an `init` function
+ * which runs before each test case is invoked. Similarly, an `exit` function
+ * may be specified which runs after every test case and can be used to for
+ * cleanup. For clarity, running tests in a test suite would behave as follows:
+ *
+ * suite.init(test);
+ * suite.test_case[0](test);
+ * suite.exit(test);
+ * suite.init(test);
+ * suite.test_case[1](test);
+ * suite.exit(test);
+ * ...;
+ */
+static struct kunit_suite example_test_suite = {
+ .name = "example",
+ .init = example_test_init,
+ .test_cases = example_test_cases,
+};
+
+/*
+ * This registers the above test suite telling KUnit that this is a suite of
+ * tests that need to be run.
+ */
+kunit_test_suite(example_test_suite);
new file mode 100644
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for struct string_stream.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/string-stream.h>
+#include <kunit/test.h>
+#include <linux/slab.h>
+
+static void string_stream_test_empty_on_creation(struct kunit *test)
+{
+ struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+
+ KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
+}
+
+static void string_stream_test_not_empty_after_add(struct kunit *test)
+{
+ struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+
+ string_stream_add(stream, "Foo");
+
+ KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+}
+
+static void string_stream_test_get_string(struct kunit *test)
+{
+ struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+ char *output;
+
+ string_stream_add(stream, "Foo");
+ string_stream_add(stream, " %s", "bar");
+
+ output = string_stream_get_string(stream);
+ KUNIT_EXPECT_STREQ(test, output, "Foo bar");
+}
+
+static struct kunit_case string_stream_test_cases[] = {
+ KUNIT_CASE(string_stream_test_empty_on_creation),
+ KUNIT_CASE(string_stream_test_not_empty_after_add),
+ KUNIT_CASE(string_stream_test_get_string),
+ {}
+};
+
+static struct kunit_suite string_stream_test_suite = {
+ .name = "string-stream-test",
+ .test_cases = string_stream_test_cases
+};
+kunit_test_suite(string_stream_test_suite);