Understanding the Problem
When dealing with test failures in mocked hardware interfaces using Ceedling, it’s crucial to first understand the root cause of the failure. Mock failures usually arise from issues such as mismatched function expectations, incorrect return values, or improper handling of hardware state. Understanding the inner workings of Ceedling’s CMock framework will significantly aid in diagnosing these issues.
Review the Mock Configuration
- Check your
project.yml file for mock configurations. Ensure that the mock options are correctly set up.
# Example snippet from project.yml
:cmock:
:mock_prefix: "Mock"
:when_no_prototypes: :warn
:enforce_strict_ordering: TRUE
- Make sure strict ordering is set as needed. With strict ordering, the order of function calls is important, and mismatches can cause test failures.
Verify Mock Function Implementations
Ensure that mocked functions match the signature of the original functions. Pay special attention to data types and return values.
Use CMock functions like ignoreAndReturn, expectAndReturn, or specific argument matching functions to ensure expected behavior.
void MockHardware_Expect_ReadData(uint8_t expected_data)
{
MockHardware_ReadData_ExpectAndReturn(expected_data);
}
Analyze Test Failures
When a test fails, Ceedling provides detailed output on what went wrong. Pay close attention to the output, which can indicate if a function was called with unexpected arguments or if a call didn't occur.
Use the Verbose mode to get more detailed logs which can aid in diagnosing problems.
ceedling test:all VERBOSE=1
Utilize Callbacks for Complex Behaviors
- If your hardware has complex behavior that is difficult to mock with simple return values, consider using callbacks to simulate dynamic responses.
void CustomCallback(CMOCK_FUNC_PTR MockHardware_Callback)
{
// Your custom logic that simulates hardware response
}
Double-Check Dependencies and Includes
Ensure all necessary headers are included and dependencies are correctly set up. Missing dependencies can lead to uninitialized mocks or undefined behavior.
Often, missing or incorrect includes in test files can lead to undefined references. Verify include paths in project.yml and test files.
Leverage Ceedling Add-ons or Plugins
- Explore if there are plugins or add-ons in Ceedling that can better serve your testing purpose. They might offer enhanced functionality for dealing with hardware mocks.
Consult Documentation and Community
Ceedling and CMock documentation is quite informative. Refer to the documentation for function specifics and examples.
Engage with the online community or forums. Other developers’ shared experiences can provide insights into unique problems.
By carefully following these strategies, you should be able to effectively resolve mock-related test failures within a Ceedling environment. Always make use of the comprehensive tools that Ceedling offers and apply systematic debugging to each problem situation.
