Homework & Coding Practice

Homework/Practice Coding Assignment (20-min)

Task: Add a Custom Error Handler for Invalid JSON Payloads

Step-by-Step Procedure:

1. Step 1: Define the Custom Error Handler:

   • Add the following middleware to app.js:

     javascript코드 복사app.use((err, req, res, next) => {
         if (err instanceof SyntaxError && err.status === 400 && 'body' in err) {
             return res.status(400).json({ error: 'Invalid JSON payload' });
         }
         next(err);
     });

2. Step 2: Simulate an Invalid JSON Payload:

   • Use Postman to send a POST request to /tasks with malformed JSON:

     json코드 복사{ "title": "Invalid JSON"

3. Step 3: Observe the Response:

   • Verify the custom error message:

     json코드 복사{ "error": "Invalid JSON payload" }

4. Step 4: Handle Other Errors:

   • Add a fallback error handler for unexpected issues:

     javascript코드 복사app.use((err, req, res, next) => {
         console.error(err.stack);
         res.status(500).send('Internal Server Error');
     });

Expected Outcomes

1. Students learn to handle dynamic routes and process JSON data in Express.

2. Students gain hands-on experience in building and testing a REST API.

3. Homework reinforces skills in creating custom error handlers and handling invalid inputs.