Advanced Error Handling Techniques in Nodejs

1. Use Try-Catch Blocks:

Wrap synchronous code that might throw exceptions in try-catch blocks.

try {
  // synchronous code that may throw an error
} catch (error) {
  // handle the error
}

2. Error-First Callbacks:

When working with asynchronous code using callbacks, follow the Node.js convention of using an error-first callback pattern. This means the first argument in the callback function should be an error object (if an error occurred), and subsequent arguments should contain data.

3. Promises with .catch():

When using Promises, use the .catch() method to handle errors that occur during asynchronous operations.

someAsyncFunction()
  .then((result) => {
    // handle success
  })
  .catch((error) => {
    // handle error
  });

4. Async/Await with Try-Catch:

When using async/await, wrap asynchronous code in try-catch blocks to handle errors in a synchronous-looking manner.

try {
  const result = await someAsyncFunction();
  // handle success
} catch (error) {
  // handle error
}

5. Centralized Error Handling Middleware:

In Express.js (or other web frameworks), you can create centralized error-handling middleware to catch and handle errors globally.

app.use((err, req, res, next) => {
  // handle the error
  res.status(err.status || 500).json({ error: err.message });
});

6. Custom Error Classes:

Define custom error classes to make error handling more structured and informative.

class MyCustomError extends Error {
  constructor(message, statusCode) {
    super(message);
    this.name = this.constructor.name;
    this.statusCode = statusCode || 500;
  }
}

7. Graceful Shutdown:

Implement graceful shutdown procedures to handle unhandled exceptions and cleanup resources before the application exits. Use the process.on('uncaughtException') and process.on('unhandledRejection') events to catch unhandled errors.

process.on('unhandledRejection', (reason, promise) => {
  // handle unhandled Promise rejections
});

process.on('uncaughtException', (error) => {
  // handle unhandled exceptions
});

8. Validation and Input Sanitization:

Validate user inputs and sanitize data to prevent errors and security vulnerabilities at the source.

Remember that error handling is a critical part of application development, and different situations may require different approaches. It's essential to consider the specific needs of your application and design your error handling strategy accordingly to ensure reliability and maintainability.