[PATCH v2 07/17] kunit: test: add initial tests

[shuah]

On 5/1/19 5:01 PM, Brendan Higgins wrote:
> Add a test for string stream along with a simpler example.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins at google.com>
> ---
>   kunit/Kconfig              | 12 ++++++
>   kunit/Makefile             |  4 ++
>   kunit/example-test.c       | 88 ++++++++++++++++++++++++++++++++++++++
>   kunit/string-stream-test.c | 61 ++++++++++++++++++++++++++
>   4 files changed, 165 insertions(+)
>   create mode 100644 kunit/example-test.c
>   create mode 100644 kunit/string-stream-test.c
> 
> diff --git a/kunit/Kconfig b/kunit/Kconfig
> index 64480092b2c24..5cb500355c873 100644
> --- a/kunit/Kconfig
> +++ b/kunit/Kconfig
> @@ -13,4 +13,16 @@ config KUNIT
>   	  special hardware. For more information, please see
>   	  Documentation/kunit/
>   
> +config KUNIT_TEST
> +	bool "KUnit test for KUnit"
> +	depends on KUNIT
> +	help
> +	  Enables KUnit test to test KUnit.
> +

Please add a bit more information on what this config option
does. Why should user care to enable it?

> +config KUNIT_EXAMPLE_TEST
> +	bool "Example test for KUnit"
> +	depends on KUNIT
> +	help
> +	  Enables example KUnit test to demo features of KUnit.
> +

Same here.

>   endmenu
> diff --git a/kunit/Makefile b/kunit/Makefile
> index 6ddc622ee6b1c..60a9ea6cb4697 100644
> --- a/kunit/Makefile
> +++ b/kunit/Makefile
> @@ -1,3 +1,7 @@
>   obj-$(CONFIG_KUNIT) +=			test.o \
>   					string-stream.o \
>   					kunit-stream.o
> +
> +obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
> +
> +obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	example-test.o
> diff --git a/kunit/example-test.c b/kunit/example-test.c
> new file mode 100644
> index 0000000000000..3947dd7c8f922
> --- /dev/null
> +++ b/kunit/example-test.c
> @@ -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 at 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_module 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 module
> + * 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 module.
> +	 */
> +	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 module would behave as follows:
> + *
> + * module.init(test);
> + * module.test_case[0](test);
> + * module.exit(test);
> + * module.init(test);
> + * module.test_case[1](test);
> + * module.exit(test);
> + * ...;
> + */
> +static struct kunit_module example_test_module = {
> +	.name = "example",
> +	.init = example_test_init,
> +	.test_cases = example_test_cases,
> +};
> +
> +/*
> + * This registers the above test module telling KUnit that this is a suite of
> + * tests that need to be run.
> + */
> +module_test(example_test_module);
> diff --git a/kunit/string-stream-test.c b/kunit/string-stream-test.c
> new file mode 100644
> index 0000000000000..b2a98576797c9
> --- /dev/null
> +++ b/kunit/string-stream-test.c
> @@ -0,0 +1,61 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * KUnit test for struct string_stream.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins at google.com>
> + */
> +
> +#include <linux/slab.h>
> +#include <kunit/test.h>
> +#include <kunit/string-stream.h>
> +
> +static void string_stream_test_get_string(struct kunit *test)
> +{
> +	struct string_stream *stream = new_string_stream();
> +	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");
> +	kfree(output);
> +	destroy_string_stream(stream);
> +}
> +
> +static void string_stream_test_add_and_clear(struct kunit *test)
> +{
> +	struct string_stream *stream = new_string_stream();
> +	char *output;
> +	int i;
> +
> +	for (i = 0; i < 10; i++)
> +		string_stream_add(stream, "A");
> +
> +	output = string_stream_get_string(stream);
> +	KUNIT_EXPECT_STREQ(test, output, "AAAAAAAAAA");
> +	KUNIT_EXPECT_EQ(test, stream->length, 10);
> +	KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
> +	kfree(output);
> +
> +	string_stream_clear(stream);
> +
> +	output = string_stream_get_string(stream);
> +	KUNIT_EXPECT_STREQ(test, output, "");
> +	KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
> +	destroy_string_stream(stream);
> +}
> +
> +static struct kunit_case string_stream_test_cases[] = {
> +	KUNIT_CASE(string_stream_test_get_string),
> +	KUNIT_CASE(string_stream_test_add_and_clear),
> +	{}
> +};
> +
> +static struct kunit_module string_stream_test_module = {
> +	.name = "string-stream-test",
> +	.test_cases = string_stream_test_cases
> +};
> +module_test(string_stream_test_module);
> +
>