Support for custom error types?

[bjrmatos]

I like the approach of defining custom type errors in this module https://github.com/jayyvis/extend-error , I think it would be great to add this functionality

[OliverJAsh]

:+1:

Joyent recommends using “the Error's name property to distinguish errors programmatically”. However, I can't see a way to use VError with custom error types – if everything has a name of VError or WError then obviously you can no longer use the name property to distinguish programmatically.

– https://www.joyent.com/developers/node/design/errors

[davepacheco]

Thanks for the pointer! I'll take a look at extend-error. There's a branch of VError that lets you set name and other properties here:

https://github.com/davepacheco/node-verror/compare/props

but I haven't had occasion to use it in an application so I haven't integrated it into master yet.

[naddison36]

My branch of VError may have what you are looking for https://github.com/naddison36/node-verror

It preserves the name property from the error cause rather than setting the name property to VError or WError.

[iliakan]

Maybe you should allow to extend VErrors by inheritance?

Inheritance allows to use generic tests like err instanceof HttpError (catches HttpError, PageNotFoundError, ForbiddenError etc).

As a side effect, name is available (and should be supported).

[iliakan]

P.S. Maybe it is allowed to inherit from VErrors right now, but in the examples folder I don't see that as a use case.

[vipreshjha]

@iliakan If you have successfully inherited VError can you provide an example . Cause in the current implementation we get the VError object by calling the method of static class I have not idea how to perform inheritance in this scenario using the inbuilt Node "Util" library.

[vipreshjha]

@iliakan I just checked the docs there is also a constructor function available so I can inherit easily.

[iliakan]

oh that was so long ago I can't even remember what the issue was about. There definitely was something. Withdrawing my question cause of lack of memories.

[yunong]

@davepacheco Any updates on whether you'll merge in your branch? It'd be really nice to be able to use the new features.

[davepacheco]

@yunong I haven't really had a chance to play with it much myself, so I haven't really validated the new design. Have you tried it? Or at least looked at the API?

[figadore]

@naddison36 That is what I was looking for

[DonutEspresso]

Another alternative for folks looking is restify-errors, we built it on top of VError (thanks Dave!) and made it relatively straightforward to create custom constructors and properties.

[davepacheco]

My changes for #10 (which are out for code review) support configuring the "name", and the pattern for inheritance is better documented, too. Closing this as a dup of #10. Thanks!