Router - Error Handling

VkrunJS provides a global error-handling middleware through vkrun.error(), ensuring that both synchronous and asynchronous errors are caught and handled consistently.

Implementing Error Handling Middleware

Add the global error-handling middleware using app.error(). This middleware takes three parameters: error, req, and res. VkrunJS automatically forwards captured errors from both synchronous and asynchronous handlers to this middleware, allowing you to define a custom response.

Note: If you need custom error handling per route, use try-catch inside your controllers instead of relying on vkrun.error().

Example: Global Error Handling Middleware

import v from "vkrun";
 
// Define an asynchronous error-handling middleware
const errorHandler = async (error: any, req: v.Request, res: v.Response) => {
  console.error("Error caught:", error.message);
  res.status(500).send("Internal Server Error");
};
 
const vkrun = v.App();
 
// Add the global error middleware
vkrun.error(errorHandler);
 
// Synchronous route - error is automatically caught
vkrun.get("/example-a", (req: v.Request, res: v.Response) => {
  throw new Error("Any Error"); // Caught by the middleware
 
  res.status(200).send("GET method route");
});
 
// Asynchronous route - error is automatically caught by vkrun.error()
vkrun.get("/example-b", async (req: v.Request, res: v.Response) => {
  await someAsyncOperation(); // If this throws an error, it's caught by `vkrun.error()`
  res.status(200).send("Async GET method route");
});
 
// Custom error handling for a specific route using try-catch
vkrun.get("/example-c", async (req: v.Request, res: v.Response) => {
  try {
    await someAsyncOperation();
    res.status(200).send("Async GET method route");
  } catch (error) {
    res.status(400).send("Custom error message for this route"); // Custom error response
  }
});
 
vkrun.server().listen(3000, () => {
  console.log("Vkrun started on port 3000");
});

Key Points

• Global Error Handling: vkrun.error() captures errors in both synchronous and asynchronous routes, ensuring uniform error handling across the application.
• Custom Error Handling per Route: If a specific route requires custom error responses, use try-catch inside the controller.
• Centralized Error Handling: The global error middleware ensures a consistent error response and prevents the application from crashing due to unhandled exceptions.

Best Practice

• Use vkrun.error() for global error handling, catching all unhandled exceptions in one place.
• Use try-catch inside controllers for fine-grained, per-route error handling, especially when you need custom HTTP status codes or responses.

For more details on middleware, see the VkrunJS Middleware Documentation.