RIOT/tests

Running and creating tests

There are a number of tests included in RIOT. They are located in the tests folder. These tests allow basic functionality to be verified as well as provide an example of usage.

Implementing automated tests

The goal is to be able to run all tests in a sequential way for as many targets as possible.

As some board can't be reset without a manual trigger tests should be implemented with some kind of synchronization. This can be done in two ways:

• use test_utils_interactive_sync when uart input/output does not need to be disabled for the test. This is enabled by default.
• set up the test in a loop so the test script will be able so sync with some kind of start condition in the test.

The module for the first option is test_utils_interactive_sync and is set as a default module in Makefile.tests_common. It can be disabled by setting in the application makefile DISABLE_MODULE += test_utils_interactive_sync. The python test script will adapt to it automatically.

When using the shell module, test_utils_interactive_sync will use the shell itself to synchronize, and will not use test_utils_interactive_sync(); function to synchronize. Some times you will want to synchronize before the start of the script and use test_utils_interactive_sync(); function (e.g.: tests/ps_schedstatistics). For these cases you can disable test_utils_interactive_sync_shell module in the application Makefile: DISABLE_MODULE += test_utils_interactive_sync_shell.

Running automated tests

Some tests can be performed automatically. The test automation scripts are defined in the <test_application>/tests/ folder. They are written in python and interact through the uart with the test application code running on a board to do the validation. It is recommended to flash the board with the test just before running it because some platforms cannot be reset while testing.

From the test application directory run:

BOARD=<board_of_your_choice> make flash test

An automated way of knowing if a test is available is to execute the 'test/available' target from the test application directory. It executes without error if tests run by 'make test' are present.

make test/available

Automated Tests Guidelines

When using pexpect $ is useless for matching the end of a line, instead use \r\n(pexpect end-of-line).

Beware of + and * at the end of patterns. These patterns will always get a minimal match (non-greedy).(pexpect end-of-patterns) This can be an issue when matching groups and using the matched groups to verify some kind of behavior since * could return an empty match and + only a subset.

This is especially prevalent since printf() is buffered so the output might not arrive in a single read to pexpect.

To avoid this make sure to match a non-ambiguous character at the end of the pattern like \r\n, \s, \), etc..

don't:

    child.expect(r'some string: (\d+)')

do:

    child.expect(r'some string: (\d+)\r\n')

    child.expect(r'some string: (\d+)\s')

    child.expect(r'some string: (\d+) ,')

Use expect() instead of assert()

In order to make a test application functional in all cases, use expect() instead of assert(). The former works like the latter, but will still be compiled in if NDEBUG is defined. This is useful to keep a test application working even when compiling with -DNDEBUG, allowing for the code-under-test to be compiled with that flag. Otherwise, the application would force compiling all tested code with assertions enabled. expect() is defined in the header test_utils/expect.h.

Interaction through the uart

Tests implemented with testrunner use the cleanterm target that provides an interaction without adding extra text output or input handling. It can currently be expected to have unmodified line based interaction with the board.

The expected behavior is verified with the test in tests/test_tools.

Tests cannot rely on having on all boards and terminal programs:

• unbuffered input
• allowing sending special characters like ctrl+c/ctrl+d