Implement DELETE Endpoint For Recommendation Requests

by TheNnagam 54 views

Hey team! Let's get this DELETE endpoint for the RecommendationRequest table up and running! This guide walks you through the steps to implement a crucial functionality: removing specific records based on their ID. We'll cover the code, testing, and documentation to ensure this endpoint works smoothly both locally and in production. Ready to dive in?

Setting the Stage: Dependencies and Prerequisites

Before we start coding, let's make sure we're on the right track. This issue depends on the successful completion of the "Create RecommendationRequestController..." issue. Make sure that base is solid, since we'll be building on it. Once that's done, we can move forward with confidence, knowing we have the necessary foundation. This will ensure we have all the required components like the controller, and any basic configurations. This is kind of like making sure you have all the ingredients before you start baking a cake, if you know what I mean.

The Importance of Order

Dependencies are super important in software development. They ensure that we build things in a logical order, minimizing errors and making sure everything works as expected. So, double-check that the prerequisites are met before moving on. This might involve pulling the latest changes from the main branch, resolving any merge conflicts, and verifying that the basic structure is set up. This also applies to testing, which has its own dependency considerations. If there are tests that rely on the existence of this endpoint, we will have to wait until it is created. It's like making sure all your tools are in place before you start building. Without the right dependencies, you might find yourself stuck, unable to complete the task.

Deep Dive: Crafting the DELETE Endpoint

Alright, let's get our hands dirty with the code. Our goal is to create a DELETE endpoint that removes a specific record from the RecommendationRequest table. This endpoint will be accessible via a URL like /api/RecommendationRequest?id=123. The ID parameter in the URL will tell the endpoint which record to delete. Now, let's break down the process step by step:

Code Snippets and Implementation

We will need to add a method with the @DeleteMapping annotation to our RecommendationRequestController.java file. This is the heart of our endpoint. The annotation specifies that this method will handle DELETE requests. Then, we need to add the code for the DELETE method from the example controller to the RecommendationRequestController.java file. And, we'll customize it for our database table, making sure it targets the RecommendationRequest table and handles the ID lookup correctly. We're going to use the @RequestParam annotation to grab the ID from the URL, so we can identify the specific record to delete. This is how we take the id passed in the request and use it to find the record. If the record with the given ID exists, we will delete it. If the record is found, we should return a 200 (OK) status code and a message like "record 123 deleted". If the record is not found, we will return a 404 (Not Found) status code and the message "record 123 not found". Think of it like this: the server is searching for a file; if it finds it, it deletes it. If it doesn't, it returns an error.

Error Handling and Edge Cases

We need to make sure the server handles the edge cases. It has to gracefully deal with situations where the requested record doesn't exist. This is where proper error handling comes in, ensuring the application remains stable and provides informative feedback to the user. Proper error handling includes checking if the record exists before attempting to delete it. If the record isn't found, you should throw an EntityNotFoundException with an appropriate message.

Swagger UI Documentation

Swagger UI is your best friend when it comes to API documentation. It automatically generates interactive API documentation from your code annotations. Make sure your DELETE endpoint is well-documented in Swagger UI so that anyone on the team can easily understand how to use it. This will include details about the endpoint's URL, the expected parameters, the possible responses (like 200 OK and 404 Not Found), and examples of how to make the request. Keep the documentation clear, concise, and easy to understand. Well-documented endpoints save time and effort by providing a quick reference for developers and anyone else interacting with the API.

Testing, Testing, and More Testing!

Creating tests is a must. We need to make sure our DELETE endpoint works as expected and doesn't break anything else. We will be copying the tests that pertain to the DELETE method from the example controller, and pasting them into RecommendationRequestControllerTests.java and then edit them to match your database table. The tests will also cover a few scenarios:

Core Test Cases

  • Successful Deletion: Ensure that when a record exists, the endpoint deletes it and returns a 200 OK status. Check the database to confirm the record is actually gone. This confirms that the record can be deleted successfully.
  • Record Not Found: Verify that if the record doesn't exist, the endpoint returns a 404 Not Found status with the correct message. This confirms the endpoint handles the case where the record doesn't exist correctly.
  • Integration Tests: You might need integration tests to simulate real-world scenarios. Make sure to test the endpoint with the actual database. This will help you catch any unexpected behavior that might occur when the endpoint interacts with the database. These tests will include setting up a test database, inserting test data, calling the endpoint, and verifying the results.

Code Coverage and Mutation Testing

We want to make sure our tests cover all the code paths. We are going to use Jacoco for coverage reports and Pitest for mutation testing. Jacoco will tell us how much of our code is covered by tests, and Pitest will make sure that our tests are effective by finding and eliminating mutations in our code.

  • Jacoco for Full Coverage: Jacoco is a code coverage tool. It will generate reports showing what percentage of your code is covered by your tests. Aim for high code coverage – the more your tests cover, the more confidence you can have in the quality of your code. This includes all branches of your code, including error handling. Check the Jacoco report regularly to make sure your tests are comprehensive.
  • Pitest for Mutation Testing: Pitest is a mutation testing tool. It helps ensure that your tests are effective by introducing small changes (mutations) into your code and checking if your tests fail. If your tests don't catch the mutations, it means your tests are not doing a good job of validating your code. Mutation testing is essential for catching gaps in your testing. If Pitest says a mutation survived, it means your tests didn't catch the error. You need to add more tests to cover that code. It will make sure your tests really are catching errors and ensuring the code is correct.

Final Steps: Completion and Review

We're almost there! Once you've implemented the endpoint, tested it thoroughly, and made sure everything is documented and working as expected, it's time to submit your work. Here’s a summary of the steps you need to take:

Creating a Pull Request

  1. Code Review: Follow the standard procedure. Create a pull request (PR) with a clear title and a detailed description of your changes. It should also include a reference to the related issue (e.g., "Closes #n").
  2. Request Reviews: Request reviews from your team members. Code reviews are important. Reviewers can catch any issues or suggest improvements. This will help make sure your code is up to standards and follows team guidelines.
  3. Address Feedback: Be ready to address any feedback from your reviewers. Code reviews are a learning opportunity. Be open to suggestions and willing to make changes. This will improve the quality of your code and help the entire team. After the review, make any necessary changes.
  4. Testing After Changes: After making any changes suggested by your reviewers, make sure you rerun all your tests to confirm everything still works correctly.

Testing in Different Environments

  • Localhost: Verify that the endpoint works correctly on your local machine. Ensure that you can successfully make DELETE requests. Test all the scenarios we covered in the testing section. This also allows you to test the API locally, before deploying it to other environments.
  • Dokku: Test your endpoint on Dokku. Dokku is a platform-as-a-service (PaaS) that lets you deploy and manage applications on a single server or a cluster. Ensure that the endpoint is functioning correctly in a production-like environment. This confirms that the endpoint works well in a production-like environment. This step also involves checking if the endpoint integrates well with other components.

The Next Steps

After submitting your PR, check if any of your teammates have any PRs waiting for review. You can help by reviewing their code. When you are done with the work for RecommendationRequest, help your teammates, so that the team will be ready to submit on Canvas by the deadline.

Conclusion

That’s it, guys! We've covered how to implement the DELETE endpoint for our RecommendationRequest table. Now you have the knowledge and the steps you need to create the endpoint, test it, and make sure it's documented. Remember, coding is a team effort. Always communicate, collaborate, and help each other out. Good luck, and happy coding!