Chapter 46: Error Handling in C

Unified error format with code, message, detail. In this chapter, you will learn error handling in depth with C code examples, explanations, and best practices.

Overview

This chapter covers error handling for Kungfu.js developers using C. We will start with the basics, move through practical examples, and end with advanced techniques and common pitfalls.

Why This Matters

Understanding error handling is essential because it is a core part of building web applications. Every real-world app needs to handle unified error format with code, message, detail. Skipping this chapter would leave a gap in your knowledge that would cause problems later.

Code Example

Here is how to handle this in C:

// Error handling
app.get('/users/:id', (req) => {
    const id = req.param('id');
    if (!id) {
        return {
            status: 400,
            body: JSON.stringify({
                error: {
                    code: 400,
                    message: "Missing user ID",
                    detail: "The :id parameter is required",
                    suggestion: "Check the URL format"
                }
            })
        };
    }
    // ... handle request
});

Common Mistakes

• Not reading the documentation: Always check the API reference when something does not work as expected.
• Skipping security: Never disable the default middleware unless you have a very good reason. Security is not optional.
• Not testing: Write tests for your handlers. Kungfu.js makes this easy with the built-in test utilities.

Summary

In this chapter, you learned about error handling in C. You saw code examples, understood how things work under the hood, and learned about common mistakes to avoid.

What is Next?

In chapter 47, we will cover Testing Your App: Unit tests, integration tests, fuzz testing.