How to Fix: Typescript - Extending Error class

TS error handling with custom class name

The Problem

The issue you're experiencing occurs when trying to throw a custom error with a specific class name printed in the console. This affects developers who want to create their own custom error classes.This problem can be frustrating because it prevents developers from fully utilizing TypeScript's features, such as creating custom error classes. In this guide, we'll walk you through the steps to resolve this issue using TypeScript.
🔍 Why This Happens

                The root cause of this issue lies in how TypeScript handles inheritance and prototype chaining when extending built-in classes like Error.When a class extends Error, it doesn't create a new instance of the Error class but rather inherits its properties and behavior.

            🛠️ Step-by-Step Verified Fixes

                Using the `name` property to set the custom error class name

                    Step 1: To resolve this issue, you can use the `name` property to explicitly set the custom error class name when extending Error.Step 2: In your CustomError class, add the line `this.name = 'CustomError';` to the constructor to ensure that the correct class name is printed in the console.Step 3: Here's an example of how this should look: `class CustomError extends Error { constructor(message: string) { super(`Lorem '${message}' ipsum dolor.`); this.name = 'CustomError'; } }`



                Using a wrapper function to create the custom error class

                    Step 1: Alternatively, you can use a wrapper function to create a new instance of Error and set its name property.Step 2: Create a new class that extends Object (which is the base class for all objects in JavaScript) instead of Error.Step 3: Use this new class as a wrapper around Error by calling it with `new CustomError(message)` when throwing an error, like so: `throw new (class { constructor(message: string) { super(`Lorem '${message}' ipsum dolor.`); } })('foo');`


            ✨ Wrapping Up
            By following these steps, you should be able to throw a custom error with your class name printed in the console instead of Error. Remember to use the `name` property or create a wrapper function to achieve this.

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Full step-by-step guide with screenshots: Read the complete fix here

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