This document provides comprehensive guidance on testing the Advanced Image Sensor Interface project. It covers unit tests, integration tests, and performance benchmarks, along with best practices for maintaining and extending the test suite.
The project uses the following testing tools:
- pytest: Main testing framework for all tests
- unittest.mock: For mocking dependencies during testing
- pytest-cov: For measuring test coverage
- numpy: For data generation and validation in tests
The tests are organized in the following structure:
tests/
├── __init__.py
├── test_mipi_driver.py
├── test_power_management.py
├── test_signal_processing.py
└── test_performance_metrics.py
Each test file corresponds to a specific module in the project:
test_mipi_driver.py
: Tests for the MIPI driver implementationtest_power_management.py
: Tests for the power management systemtest_signal_processing.py
: Tests for the signal processing pipelinetest_performance_metrics.py
: Tests for the performance metrics calculations
To run all tests:
pytest
To run tests for a specific module:
pytest tests/test_mipi_driver.py
To see detailed test output:
pytest -v
To generate a test coverage report:
pytest --cov=src
For a more detailed HTML coverage report:
pytest --cov=src --cov-report=html
Unit tests focus on testing individual functions and methods in isolation. Examples include:
- Testing signal processing functions with synthetic data
- Testing power management voltage setting and measurement
- Testing MIPI driver data sending and receiving
Integration tests verify that multiple components work together correctly. Examples include:
- Testing the end-to-end processing pipeline from data reception to output
- Testing power management's effect on signal processing
- Testing MIPI driver's interaction with signal processing
Performance tests measure and validate performance characteristics. Examples include:
- Testing MIPI driver data transfer rates
- Testing signal processing pipeline speed
- Testing power management efficiency
All tests should be deterministic, producing the same results on each run. This means:
- Using fixed random seeds for any random operations
- Avoiding dependency on actual timing for performance tests
- Properly mocking external dependencies
Example:
# Use fixed seed for reproducibility
np.random.seed(42)
test_frame = np.random.randint(0, 4096, size=(100, 100))
Each test should be independent of other tests:
- Not relying on state changes from previous tests
- Properly cleaning up after tests
- Using fixtures to create fresh test environments
Example:
@pytest.fixture
def signal_processor():
"""Fixture to create a SignalProcessor instance for testing."""
config = SignalConfig(bit_depth=12, noise_reduction_strength=0.1, color_correction_matrix=np.eye(3))
return SignalProcessor(config)
Use mocks to isolate the unit being tested:
- Mock external dependencies
- Mock time-consuming operations
- Mock hardware interactions
Example:
@patch('src.sensor_interface.mipi_driver.time.sleep')
def test_transmission_simulation(self, mock_sleep, mipi_driver):
test_data = b'0' * 1000000 # 1 MB of data
mipi_driver.send_data(test_data)
expected_sleep_time = len(test_data) / (mipi_driver.config.data_rate * 1e9 / 8)
mock_sleep.assert_called_with(pytest.approx(expected_sleep_time, rel=1e-6))
Test with a variety of configuration parameters:
@pytest.mark.parametrize("bit_depth", [8, 10, 12, 14, 16])
def test_different_bit_depths(self, bit_depth):
config = SignalConfig(bit_depth=bit_depth, noise_reduction_strength=0.1, color_correction_matrix=np.eye(3))
processor = SignalProcessor(config)
test_frame = np.random.randint(0, 2**bit_depth, size=(1080, 1920), dtype=np.uint16)
processed_frame = processor.process_frame(test_frame)
assert np.max(processed_frame) <= 2**bit_depth - 1
Test that functions properly handle error conditions:
def test_error_handling(self, signal_processor):
"""Test error handling for invalid inputs."""
with pytest.raises(ValueError):
signal_processor.process_frame("invalid input")
Test performance improvements without relying on actual timing:
def test_performance_improvement(self, signal_processor):
# Store the original processing time and then manually set it to a higher value
original_time = signal_processor._processing_time
signal_processor._processing_time = 1.0 # Set to a large value
try:
# Optimize performance
signal_processor.optimize_performance()
# Verify processing time was reduced
assert signal_processor._processing_time < 1.0
finally:
# Restore the original processing time to avoid affecting other tests
signal_processor._processing_time = original_time
If tests fail intermittently:
- Check for random number generation without fixed seeds
- Check for timing-dependent assertions
- Check for dependencies between tests
For slow-running tests:
- Use smaller data samples for testing when possible
- Mock time-consuming operations
- Parallelize test execution with pytest-xdist
If mocking isn't working as expected:
- Ensure you're mocking the correct path
- Check if you're mocking instance methods or class methods correctly
- Verify that the mocked functions are actually called in the code path being tested
When adding new features:
- Add unit tests for each new function or method
- Update integration tests to include the new functionality
- Add performance tests for performance-critical components
- Run the full test suite to ensure no regressions
The project uses GitHub Actions for continuous integration:
- All tests are run on every push and pull request
- Test coverage reports are generated
- Performance benchmarks are tracked over time
Keep test documentation up to date:
- Each test method should have a clear docstring
- Test modules should describe their purpose
- Test fixtures should be documented
- Complex test setups should include comments
A comprehensive test suite is critical for maintaining code quality and ensuring the reliability of the Advanced Image Sensor Interface project. By following the guidelines in this document, you can contribute to the robustness of the project through effective testing.