dasilvacontin / subclass-error

:anger: JS Error subclasser.

subclass-error

Workaround for subclassing errors. Both instanceof and stack are functional.

Install

$ npm install --save subclass-error

Usage

var SubclassError = require('subclass-error');

var ClientError = SubclassError("ClientError", {statusCode:400});
var ForbiddenError = SubclassError("ForbiddenError", ClientError, {statusCode:403});

var clientErr = new ClientError ();

clientErr instanceof Error // true
clientErr instanceof ClientError // true
clientErr instanceof ForbiddenError // false
clientErr.statusCode // 400

var forbidErr = new ForbiddenError ();

forbidErr instanceof Error // true
forbidErr instanceof ClientError // true
forbidErr instanceof ForbiddenError // true
forbidErr.statusCode // 403

function hungry () {
	throw new ForbiddenError ("wow, much forbidden, very subclass");
}

hungry();
/* 
	ForbiddenError: wow, much forbidden, very subclass
	    at hungry (filePath:19:8)
	    etc expected stack
*/

SubclassError(name, [error, properties])

Creates a new subclass of error (if given) or Error (by default). The instances of the new subclass will inherit data in the optional properties parameter.

Why?

I couldn't find any existing solution in which both instanceof and stack worked as you would expect, back when I created this module.

License

MIT © David da Silva