GET Endpoint For Single HelpRequest Record

Hey guys! In this guide, we're going to dive into adding a GET endpoint to our HelpRequest table. This endpoint will allow us to retrieve a single record based on its ID. It's a crucial step in building a robust and user-friendly application. So, let's get started!

Dependencies

Before we jump into the code, it's important to note that this task relies on the completion of the "Create HelpRequestController..." issue. Make sure that's done before you proceed. This ensures we have the foundational structure in place to build upon.

Overview

Our main goal here is to implement a method that can fetch a specific HelpRequest record from the database using its ID. We'll be using the @GetMapping annotation to map HTTP GET requests to our method. This method will take an ID as a @RequestParam, perform a lookup in the database, and return the record as a JSON object. If no matching record is found, we'll throw an EntityNotFoundException to indicate that the request was unsuccessful. Think of it as adding a super-efficient search feature to our HelpRequest system. We want to make it super easy to find individual requests, and this GET endpoint is the key.

We'll also be adding tests to ensure our endpoint works perfectly. Tests are super important because they help us catch bugs early and make sure our code is reliable. No one wants an endpoint that randomly decides not to work, right? So, we're going to write some solid tests.

What We'll Achieve

Essentially, we're building a way to ask our system, "Hey, show me HelpRequest number 123!" and get back all the details in a neat, JSON package. If that HelpRequest doesn't exist, we'll let the user know with a clear error message.

Acceptance Criteria

To make sure we're on the right track, we have a few key criteria to meet:

• Endpoint Functionality:

  • We need to create an endpoint GET /api/HelpRequest?id=123 in HelpRequestController.java. This endpoint should:
    • Return the JSON representation of the HelpRequest record with ID 123 if it exists in the database.
    • Return a 404 status code and the error message id 123 not found if the record does not exist.
  • This is the core of our task. We want to be able to hit this endpoint and reliably get back the right information.

• Swagger-UI Documentation:

  • The Swagger-UI documentation for this endpoint should be clear and comprehensive. Any team member should be able to understand how to use the endpoint based on the documentation. Think of Swagger-UI as the instruction manual for our API. We want it to be crystal clear.

• Localhost Testing:

  • The endpoint must function correctly when tested on our local development environment. This is where we get to play around and make sure everything works before we deploy.

• Dokku Deployment:

  • The endpoint must function correctly when deployed to Dokku, our deployment platform. This ensures our code works not just on our machines but also in a production-like environment.

• Test Coverage:

  • We need to achieve full test coverage (Jacoco) for the new code in HelpRequestController.java. This means we're writing enough tests to cover all the different scenarios our code might encounter.

• Mutation Test Coverage:

  • We also need full mutation test coverage (Pitest) for the new code in HelpRequestController.java. Mutation testing helps us ensure our tests are robust and actually catch potential issues.

Breaking Down the Criteria

Let's break this down a little more. We're not just writing code; we're building a feature that needs to be:

1. Functional: It has to do what it's supposed to do—fetch the right data or give the right error.
2. Documented: It needs to be easy for others (and our future selves) to understand how to use it.
3. Tested: We need to be confident it works correctly in different environments and situations.

Step-by-Step Implementation

Now, let's talk about how we're going to make this happen. Here's a step-by-step breakdown of the implementation process:

1. Implement the GET Endpoint in HelpRequestController.java

• First, we'll add a new method to our HelpRequestController. This method will handle the GET request.
• We'll use the @GetMapping annotation to map the request URL (e.g., /api/HelpRequest) to this method.
• Inside the method, we'll extract the id from the @RequestParam.
• We'll then use a service or repository method (depending on our architecture) to fetch the HelpRequest record from the database based on the provided ID.
• If a record is found, we'll return it as a JSON object. This usually involves serializing the HelpRequest object into JSON format.
• If no record is found, we'll throw an EntityNotFoundException. This exception will be caught by our global exception handler (which we should already have set up) and will return a 404 status code with an appropriate error message.

Think of this step as setting up a detective who can find a specific HelpRequest based on its ID. The detective needs to know where to look (the database), how to identify the HelpRequest (the ID), and what to do if they can't find it (throw an error).

2. Document the Endpoint in Swagger-UI

• We'll use Swagger annotations (e.g., @ApiOperation, @ApiParam, @ApiResponse) to document our new endpoint. These annotations provide metadata that Swagger-UI uses to generate the API documentation.
• We'll describe the purpose of the endpoint, the expected parameters (in this case, the id), and the possible responses (success with the JSON object, or failure with a 404 error).

This step is like writing the instructions for our detective. We need to tell people what the detective does, what information they need, and what to expect as a result.

3. Write Unit Tests

• We'll write unit tests to verify that our endpoint works as expected. This includes:
  • Testing the successful retrieval of a HelpRequest record.
  • Testing the scenario where the record is not found (resulting in an EntityNotFoundException).
  • Testing with invalid input (e.g., a non-numeric ID).

Unit tests are like giving our detective practice scenarios. We want to make sure they can handle all sorts of situations, from finding the right HelpRequest to dealing with trick questions.

4. Run Jacoco for Test Coverage

• We'll run Jacoco, a code coverage tool, to ensure we have full test coverage for our new code. Jacoco will tell us which lines of code are executed by our tests and which are not.
• If we find any uncovered lines, we'll write additional tests to cover them.

Jacoco is like a checklist for our detective training. It makes sure we've covered all the important skills and haven't missed anything.

5. Run Pitest for Mutation Testing

• We'll run Pitest, a mutation testing tool, to ensure our tests are effective. Pitest will introduce small changes (mutations) into our code and check if our tests can detect these changes.
• If our tests fail to detect a mutation, it means our tests are not strong enough, and we need to improve them.

Pitest is like a final exam for our detective. It throws curveballs and tricky situations to make sure our detective is truly ready for anything.

6. Test Locally and Deploy to Dokku

• We'll test the endpoint locally to make sure it works in our development environment.
• Then, we'll deploy the changes to Dokku and test the endpoint in a production-like environment.

This is like sending our detective out into the real world. We want to make sure they can handle cases both in the training room and in the field.

Coding Time

Now that we have a solid plan, let's get to the fun part: writing the code! Remember to break the task into smaller, manageable chunks and test frequently. This will help you stay on track and catch any issues early.

What to Do Next

Once you've completed the implementation and testing, it's time to create a pull request (PR). Here are the steps to follow:

1. Create a PR:

   • Make sure your PR has a clear and descriptive title.
   • Include a detailed description of the changes you've made.
   • Add the text Closes #n to the PR description, where n is the issue number. This will automatically close the issue when the PR is merged.
   • Drag the issue to the "In Review" column on the project board.
   • Request reviewers for your PR.

2. Review PRs:

   • Check to see if any of your fellow team members have PRs that need to be reviewed. Code review is a crucial part of the development process, so make sure to contribute!

3. Assign Next Issue:

   • Assign yourself the next incomplete issue for your database table (HelpRequest).
   • Follow the usual steps: assign to self, drag to "In Progress", and start a new branch.

4. Focus on HelpRequest Issues:

   • When you are done with all issues for HelpRequest, please give your full attention to helping others on your team to complete the sprint. Teamwork makes the dream work! We want to make sure the team is ready to submit on Canvas by the deadline.

Collaboration is Key

Remember, software development is a team sport. Don't hesitate to ask for help or offer assistance to your teammates. The more we collaborate, the better our code will be, and the more we'll learn.

Conclusion

Adding a GET endpoint for single HelpRequest records is a significant step in building a complete and user-friendly application. By following the steps outlined in this guide, you'll be well on your way to creating a robust and reliable feature. So, go forth and code! And remember, have fun along the way.