README.md

Testing

Cmocka is used as the unit testing framework for firmware.

Build test suites

Use the following command to build all test suites:

$ scons build-tests

It's also possible to build a specific test suite, e.g. the timer test suite:

$ scons tests/common/timer/

Run test suites

Run all test suites:

$ scons coverage

Run a specific test suite, e.g. the timer test suite.

$ build/unit_tests/timer/TestRunner

Add a new test suite

1. Add a new directory for the test suite in tests. It's important that the directory structure is the same as in the src directory. Assume we want to add a test suite for the src/main/encoder module, then we create tests/main/encoder.

2. Create a SConscript file with the following content

   import os
   
   Import(['*'])
   
   env.Append(CPPPATH=[
       '<PATH_TO_INCLUDE>'
   ])
   
   env.Append(LINKFLAGS=[
       '-Wl,--wrap=<FUNCTION_TO_MOCK>'
   ])
   
   SOURCE = Glob('*.c')
   OBJECTS = env.Object(source=SOURCE)
   
   Return('OBJECTS')

3. Implement the test suite in test_MODULE_NAME.c. A basic template is included below but the existing test suites is the best place to learn how to write tests.

   #include <stdarg.h>
   #include <stddef.h>
   #include <setjmp.h>
   #include <cmocka.h>
   
   void test_SomeImportantTest(void **state)
   {
       /* Implement test case here. */
   }
   
   int main(void)
   {
       const struct CMUnitTest tests[] =
       {
           cmocka_unit_test(test_SomeImportantTest)
       };
       return cmocka_run_group_tests(tests, NULL, NULL);
   }

4. Enable the test by adding the full module path to the modules list in the SConstruct file.

   modules = [
       os.path.join('utility', 'CRC'),
       os.path.join('utility', 'List'),
       os.path.join('utility', 'FIFO'),
       os.path.join('main', 'encoder'),
       os.path.join('main', 'interface'),
       os.path.join('common', 'timer')
   ]

5. Thats all! You can now build and run your new test suite.

GDB

If a test fails with segmentation fault GDB is a great tool to use to track down the fault.

$ gdb build/unit_tests/timer/TestRunner

This will load the test application into GDB and present the GDB console.