fhellwig/rest-error

Provides the RestError class and associated factory methods.

rest-error

Provides the RestError class and associated factory methods.

Usage

$ npm install --save rest-error

const RestError = require('rest-error');

function sqrt(val) {
	if (val < 0) {
	    throw RestError.badRequest('Value %d cannot be negative.', val);
	} else {
	    return Math.sqrt(val);
    }
}

let err = RestError.internalServerError('Cannot connect to the database.');

console.log(err.toString());
// Error: 500 (Internal Server Error) Cannot connect to the database.

The badRequest method and internalServerError method are factory methods. No new keyword is required. There is one factory method for each of the 400- and 500-series errors.

If you want to call the constructor yourself, you can:

function sqrt(val) {
	if (val < 0) {
	    throw new RestError(400, 'Bad Request', util.format('Value %d cannot be negative.', val));
	} else {
	    return Math.sqrt(val);
    }
}

As you can see, using the factory method...

• is more readable,
• does not require the new keyword,
• includes the descriptive text, and
• handles util.format arguments.

You can also pass in an Error object...

let err = new Error('That record already exists.');

let conflict = RestError.conflict(err);

console.log(conflict.toString());
// Error: 409 (Conflict) That record already exists.

This is useful when wrapping a library error into an error for your REST API.