.. _testing: Test Framework ############### The Zephyr Test Framework (Ztest) provides a simple testing framework intended to be used during development. It provides basic assertion macros and a generic test structure. The framework can be used in two ways, either as a generic framework for integration testing, or for unit testing specific modules. Quick start - Integration testing ********************************* A simple working base is located at :file:`samples/testing/integration`. Just copy the files to ``tests/`` and edit them for your needs. The test will then be automatically built and run by the sanitycheck script. If you are testing the **bar** component of **foo**, you should copy the sample folder to ``tests/foo/bar``. It can then be tested with:: ./scripts/sanitycheck -s tests/foo/bar/test The sample contains the following files: CMakeLists.txt .. literalinclude:: ../../../samples/testing/integration/CMakeLists.txt :language: CMake :linenos: testcase.yaml .. literalinclude:: ../../../samples/testing/integration/testcase.yaml :language: yaml :linenos: prj.conf .. literalinclude:: ../../../samples/testing/integration/prj.conf :language: text :linenos: src/main.c (see :ref:`best practices `) .. literalinclude:: ../../../samples/testing/integration/src/main.c :language: c :linenos: .. contents:: :depth: 1 :local: :backlinks: top A test case project may consist of multiple sub-tests or smaller tests that either can be testing functionality or APIs. Functions implementing a test should follow the guidelines below: * Test cases function names should be prefix with **test_** * Test cases should be documented using doxygen * Test function names should be unique within the section or component being tested An example can be seen below:: /** * @brief Test Asserts * * This test verifies the zassert_true macro. */ static void test_assert(void) { zassert_true(1, "1 was false"); } The above test is then enabled as part of the testsuite using:: ztest_unit_test(test_assert) Listing Tests ============= Tests (test projects) in the Zephyr tree consist of many testcases that run as part of a project and test similar functionality, for example an API or a feature. The ``sanitycheck`` script can parse the testcases in all test projects or a subset of them, and can generate reports on a granular level, i.e. if cases have passed or failed or if they were blocked or skipped. Sanitycheck parses the source files looking for test case names, so you can list all kernel test cases, for example, by entering:: sanitycheck --list-tests -T tests/kernel Skipping Tests ============== Special- or architecture-specific tests cannot run on all platforms and architectures, however we still want to count those and report them as being skipped. Because the test inventory and the list of tests is extracted from the code, adding conditionals inside the test suite is sub-optimal. Tests that need to be skipped for a certain platform or feature need to explicitly report a skip using :c:func:`ztest_test_skip()`. If the test runs, it needs to report either a pass or fail. For example:: #ifdef CONFIG_TEST1 void test_test1(void) { zassert_true(1, "true"); } #else void test_test1(void) { ztest_test_skip(); } #endif void test_main(void) { ztest_test_suite(common, ztest_unit_test(test_test1), ztest_unit_test(test_test2) ); ztest_run_test_suite(common); } Quick start - Unit testing ************************** Ztest can be used for unit testing. This means that rather than including the entire Zephyr OS for testing a single function, you can focus the testing efforts into the specific module in question. This will speed up testing since only the module will have to be compiled in, and the tested functions will be called directly. Since you won't be including basic kernel data structures that most code depends on, you have to provide function stubs in the test. Ztest provides some helpers for mocking functions, as demonstrated below. In a unit test, mock objects can simulate the behavior of complex real objects and are used to decide whether a test failed or passed by verifying whether an interaction with an object occurred, and if required, to assert the order of that interaction. .. _main_c_bp: Best practices for declaring the test suite =========================================== *sanitycheck* and other validation tools need to obtain the list of subcases that a Zephyr *ztest* test image will expose. .. admonition:: Rationale This all is for the purpose of traceability. It's not enough to have only a semaphore test project. We also need to show that we have testpoints for all APIs and functionality, and we trace back to documentation of the API, and functional requirements. The idea is that test reports show results for every sub-testcase as passed, failed, blocked, or skipped. Reporting on only the high-level test project level, particularly when tests do too many things, is too vague. Here is a generic template for a test showing the expected use of :func:`ztest_test_suite`: .. code-block:: C #include extern void test_sometest1(void); extern void test_sometest2(void); #ifndef CONFIG_WHATEVER /* Conditionally skip test_sometest3 */ void test_sometest3(void) { ztest_test_skip(); } #else extern void test_sometest3(void); #endif extern void test_sometest4(void); ... void test_main(void) { ztest_test_suite(common, ztest_unit_test(test_sometest1), ztest_unit_test(test_sometest2), ztest_unit_test(test_sometest3), ztest_unit_test(test_sometest4), ); ztest_run_test_suite(common); } For *sanitycheck* to parse source files and create a list of subcases, the declarations of :func:`ztest_test_suite` must follow a few rules: - one declaration per line - conditional execution by using :func:`ztest_test_skip` What to avoid: - packing multiple testcases in one source file .. code-block:: C void test_main(void) { #ifdef TEST_feature1 ztest_test_suite(feature1, ztest_unit_test(test_1a), ztest_unit_test(test_1b), ztest_unit_test(test_1c), ztest_run_test_suite(feature1); #endif #ifdef TEST_feature2 ztest_test_suite(feature2, ztest_unit_test(test_2a), ztest_unit_test(test_2b), ztest_run_test_suite(feature2); #endif } - Do not use ``#if`` .. code-block:: C ztest_test_suite(common, ztest_unit_test(test_sometest1), ztest_unit_test(test_sometest2), #ifdef CONFIG_WHATEVER ztest_unit_test(test_sometest3), #endif ztest_unit_test(test_sometest4), ... - Do not add comments on lines with a call to :func:`ztest_unit_test`: .. code-block:: C ztest_test_suite(common, ztest_unit_test(test_sometest1), ztest_unit_test(test_sometest2) /* will fail */, /* will fail! */ ztest_unit_test(test_sometest3), ztest_unit_test(test_sometest4), ... - Do not define multiple definitions of unit / user unit test case per line .. code-block:: C ztest_test_suite(common, ztest_unit_test(test_sometest1), ztest_unit_test(test_sometest2), ztest_unit_test(test_sometest3), ztest_unit_test(test_sometest4), ... Other questions: - Why not pre-scan with CPP and then parse? or post scan the ELF file? If C pre-processing or building fails because of any issue, then we won't be able to tell the subcases. - Why not declare them in the YAML testcase description? A separate testcase description file would be harder to maintain than just keeping the information in the test source files themselves -- only one file to update when changes are made eliminates duplication. API reference ************* Running tests ============= .. doxygengroup:: ztest_test :project: Zephyr Assertions ========== These macros will instantly fail the test if the related assertion fails. When an assertion fails, it will print the current file, line and function, alongside a reason for the failure and an optional message. If the config option:`CONFIG_ZTEST_ASSERT_VERBOSE` is 0, the assertions will only print the file and line numbers, reducing the binary size of the test. Example output for a failed macro from ``zassert_equal(buf->ref, 2, "Invalid refcount")``: .. code-block:: none Assertion failed at main.c:62: test_get_single_buffer: Invalid refcount (buf->ref not equal to 2) Aborted at unit test function .. doxygengroup:: ztest_assert :project: Zephyr Mocking ======= These functions allow abstracting callbacks and related functions and controlling them from specific tests. You can enable the mocking framework by setting :option:`CONFIG_ZTEST_MOCKING` to "y" in the configuration file of the test. The amount of concurrent return values and expected parameters is limited by :option:`CONFIG_ZTEST_PARAMETER_COUNT`. Here is an example for configuring the function ``expect_two_parameters`` to expect the values ``a=2`` and ``b=3``, and telling ``returns_int`` to return ``5``: .. literalinclude:: mocking.c :language: c :linenos: .. doxygengroup:: ztest_mock :project: Zephyr