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.