Typescript Custom Error Types

Typescript custom error types

Created By: chatGPT

Custom error types allow you to create more meaningful error messages and handling in your TypeScript applications. By extending the built-in Error class, you can add additional properties and methods relevant to your specific error context. This is especially useful for improving debugging and error management in larger applications.

class CustomError extends Error {
    constructor(message: string) {
        super(message);
        this.name = 'CustomError';
    }
}

You can also create different error types for various scenarios, such as validation errors, authentication errors, or database errors. This helps categorize errors more effectively.

class ValidationError extends CustomError {
    field: string;

    constructor(message: string, field: string) {
        super(message);
        this.field = field;
        this.name = 'ValidationError';
    }
}

When throwing these errors, make sure you include relevant information. For example, if you are throwing a ValidationError, you can provide the field that triggered the error, which is crucial for debugging and handling the error gracefully in your application.

function validateInput(input: any) {
    if (!input.name) {
        throw new ValidationError('Name is required', 'name');
    }
}

To handle these custom errors, you can use a try-catch block, allowing you to differentiate between different error types and respond accordingly. This allows for better user feedback and logging.

try {
    validateInput({});
} catch (error) {
    if (error instanceof ValidationError) {
        console.error(`Validation failed for field: ${error.field}`);
    } else {
        console.error('An unexpected error occurred:', error);
    }
}