From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Orlov Date: Fri, 1 Mar 2024 16:00:42 +0000 Subject: [PATCH v3 1/4] docs: Add documentation about tests and SBIUnit In-Reply-To: <20240301160046.267814-1-ivan.orlov0322@gmail.com> References: <20240301160046.267814-1-ivan.orlov0322@gmail.com> Message-ID: <20240301160046.267814-2-ivan.orlov0322@gmail.com> List-Id: To: opensbi@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit This patch contains the documentation for SBIUnit. It describes: - What is SBIUnit - Simple test writing scenario - How we can cover static functions - How we can "mock" structures in order to test the functions which operate on them - SBIUnit API Reference Signed-off-by: Ivan Orlov --- V1 -> V2: - Use more appropriate language - Update the documentation in accordance with SBIUnit API and structure changes - Remove the redundant documentation for every SBIUNIT_* macro. - Make the documentation follow the 80-characters rule. V2 -> V3: - Fix a few typos - Provide the expected console output as it is, without following 80-chars rule - Update the example test source: use SBIUNIT_END_CASE macro instead of "{}" - Add the paragraph about the manual removal of the 'build/' directory in order to regenerate carray-related files. Currently, that's the only reliable way to regenerate them if carray Makefile variable changes, and it is going to be fixed in the future. docs/writing_tests.md | 133 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 docs/writing_tests.md diff --git a/docs/writing_tests.md b/docs/writing_tests.md new file mode 100644 index 0000000..a1f11e5 --- /dev/null +++ b/docs/writing_tests.md @@ -0,0 +1,133 @@ +Writing tests for OpenSBI +========================= + +SBIUnit +------- +SBIUnit is a set of macros and functions which simplify the test development and +automate the test execution and evaluation. All of the SBIUnit definitions are +in the `include/sbi/sbi_unit_test.h` header file, and implementations are +available in `lib/sbi/sbi_unit_test.c`. + +Simple SBIUnit test +------------------- + +For instance, we would like to test the following function from +`lib/sbi/sbi_string.c`: + +```c +size_t sbi_strlen(const char *str) +{ + unsigned long ret = 0; + + while (*str != '\0') { + ret++; + str++; + } + + return ret; +} +``` + +which calculates the string length. + +Create the file `lib/sbi/sbi_string_test.c` with the following content: + +```c +#include +#include + +static void strlen_test(struct sbiunit_test_case *test) +{ + SBIUNIT_EXPECT_EQ(test, sbi_strlen("Hello"), 5); + SBIUNIT_EXPECT_EQ(test, sbi_strlen("Hell\0o"), 4); +} + +static struct sbiunit_test_case string_test_cases[] = { + SBIUNIT_TEST_CASE(strlen_test), + SBIUNIT_END_CASE, +}; + +SBIUNIT_TEST_SUITE(string_test_suite, string_test_cases); +``` + +Then, add the corresponding Makefile entries to `lib/sbi/objects.mk`: +```lang-makefile +... +libsbi-objs-$(CONFIG_SBIUNIT) += sbi_string_test.o +carray-sbi_unit_tests-$(CONFIG_SBIUNIT) += string_test_suite +``` + +If you compiled OpenSBI with CONFIG_SBIUNIT enabled before, you may need to +manually remove the build folder in order to regenerate the carray files: +`rm -rf build/`. + +Recompile OpenSBI with CONFIG_SBIUNIT option enabled and run it in the QEMU. +You will see something like this: +``` +# make PLATFORM=generic run +... +# Running SBIUNIT tests # +... +## Running test suite: string_test_suite +[PASSED] strlen_test +1 PASSED / 0 FAILED / 1 TOTAL +``` + +Now let's try to change this test in the way that it will fail: + +```c +- SBIUNIT_EXPECT_EQ(test, sbi_strlen("Hello"), 5); ++ SBIUNIT_EXPECT_EQ(test, sbi_strlen("Hello"), 100); +``` + +`make all` and `make run` it again: +``` +... +# Running SBIUNIT tests # +... +## Running test suite: string_test_suite +[SBIUnit] [.../opensbi/lib/sbi/sbi_string_test.c:6]: strlen_test: Condition "(sbi_strlen("Hello")) == (100)" expected to be true! +[FAILED] strlen_test +0 PASSED / 1 FAILED / 1 TOTAL +``` +Covering the static functions / using the static definitions +------------------------------------------------------------ + +SBIUnit also allows you to test static functions. In order to do so, simply +include your test source in the file you would like to test. Complementing the +example above, just add this to the +`lib/sbi/sbi_string.c` file: + +```c +#ifdef CONFIG_SBIUNIT +#include "sbi_string_test.c" +#endif +``` + +In this case you should only add a new carray entry pointing to the test suite +to `lib/sbi/objects.mk`: +```lang-makefile +... +carray-sbi_unit_tests-$(CONFIG_SBIUNIT) += string_test_suite +``` + +You don't have to compile the `sbi_string_test.o` separately, because the +test code will be included into the `sbi_string` object file. + +See example in `lib/sbi/sbi_console_test.c`, where statically declared +`console_dev` variable is used to mock the `sbi_console_device` structure. + +"Mocking" the structures +------------------------ +See the example of structure "mocking" in the `lib/sbi/sbi_console_test.c`, +where the sbi_console_device structure was mocked to be used in various +console-related functions in order to test them. + +API Reference +------------- +All of the `SBIUNIT_EXPECT_*` macros will cause a test case to fail if the +corresponding conditions are not met, however, the execution of a particular +test case will not be stopped. + +All of the `SBIUNIT_ASSERT_*` macros will cause a test case to fail and stop +immediately, triggering a panic. -- 2.34.1