How to test integration between components in PHPUnit?

@domenico 

To test the integration between components in PHPUnit, you can follow these steps:

1. Set up the environment: Create a test environment that closely resembles the production environment. This may involve setting up databases, APIs, or other dependencies that your components rely on.
2. Identify the components: Determine which components you want to test and understand their dependencies. Make sure all necessary components are set up properly and are functioning.
3. Write test cases: Create test cases for the integration scenarios you want to test. Consider both positive and negative scenarios to cover all possible interactions between components.
4. Use PHPUnit's testing features: PHPUnit provides various testing features that you can utilize for integration testing. Some common ones include assertions for comparing expected and actual results, mocking to simulate the behavior of dependencies, and running test cases in isolation.
5. Set up test data: Prepare test data that represents real-world scenarios. This could involve creating mock objects or using sample data sets. Ensure that the data is properly structured and represents the expected behavior of the components.
6. Perform tests: Run the test cases and analyze the results. Look for any failures or errors in the integration between components. Use PHPUnit's reporting features to help identify issues more easily.
7. Refine and iterate: If any issues or failures are found, debug and fix the problems. Modify the test cases or environment as needed and rerun the tests until the integration is successful.
8. Automate the process: Integrate the integration tests into your continuous integration/continuous deployment (CI/CD) pipeline. This ensures that the integration remains intact as the codebase evolves and prevents any regressions.

By following these steps, you can effectively test the integration between components in PHPUnit and ensure that they work together as expected.