subclass-error

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

subclass-error

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

$ npm install subclass-error
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
*/

Creates a new subclass of 'error' (if specified) or Error (by default). The instances of the new subclass will have the same properties as those provided in the optional 'properties' parameter.

I didn't find any other workaround in which both 'instanceof' and 'stack' work as you would expect, so I ended up creating this.

MIT