Custom Error Formatter

[uphlewis]

Hi!

First of all, thanks so much for psysh, it is absolutely fundamental to my development process these days as im sure it is for many others.

Suggestion / request for comment

It would be nice to be able to specify a custom error formatter (e.g., closure) which receives the exception/throwable, and the output instance as arguments. Either a custom formatter, or at least the ability to hook into the Shell::writeException() method and e.g., write additional output to aid debugging for certain types of errors.

One example of this is in laravel projects, when a validation exception is thrown. Psysh outputs the error message, but the real substance of those exceptions is the $e->errors() array, which contains the exact validation errors which is crucial for debugging.

To demonstrate, this is the current behaviour:

What I'm aiming to be able to achieve:

Obviously there are myriad ways this could be achieved, i have a couple of ideas of how to implement a custom formatter as an optional configuration option in a safe/sensible way and am willing to prepare a PR, if this is an addition you'd be welcome to seeing in the project.

Thanks

[bobthecow]

Conceptually this feels in line with the way we use var-dumper and casters. I could get on board with it.

It'd be ideal if we could come up with a way for this to work and be useful without needing additional configuration, and without duplicating a bunch of stuff already done in var-dumper. Maybe using var-dumper automatically if there's an explicitly defined caster for that exception type? Maybe doing something with caster filters, and extending our Presenter with a presentException?

[uphlewis]

Sounds great- id have to get into the package a little more and see how casters work with var dumper. But happy to contribute something if I can!