@deltic/error-standard

A standard error base class with error codes, structured context, and cause chains.

Installation

npm install @deltic/error-standard

Usage

Defining Errors

Extend StandardError to define domain-specific errors with codes and context:

import {StandardError} from '@deltic/error-standard';

class UserNotFound extends StandardError {
    static forId(id: string) {
        return new UserNotFound(
            `User ${id} not found`,
            'USER_NOT_FOUND',
            {userId: id},
        );
    }
}

class PaymentFailed extends StandardError {
    static because(reason: string, cause: unknown) {
        return new PaymentFailed(
            `Payment failed: ${reason}`,
            'PAYMENT_FAILED',
            {reason},
            cause,
        );
    }
}

Extracting Error Messages

Use errorToMessage to safely extract a message from any thrown value:

import {errorToMessage} from '@deltic/error-standard';

try {
    await riskyOperation();
} catch (error) {
    console.log(errorToMessage(error)); // works with Error, string, or unknown
}

API Reference

StandardError

abstract class StandardError extends Error {
    constructor(
        message: string,
        code: string,
        context?: ErrorContext,
        cause?: unknown,
    )

    readonly code: string;
    readonly context: ErrorContext;
}

An abstract base class extending Error. Subclass it to define specific error types with machine-readable codes and structured context.

ErrorContext

type ErrorContext = {[index: string]: string | number | null | boolean};

errorToMessage(error: unknown): string

Extracts a message string from any value. Returns error.message for Error instances, the string itself for strings, or 'Unknown error' for anything else.

License

ISC