Add prettier dev error page

[chrismccord]

Possibly borrow Dynamo's

[slogsdon]

I'd like to contribute something for this if no one's started yet.

I like Dynamo's dev error screen, but personally, I would want a bit more information for debug purposes, maybe something similar to this. Thoughts?

[josevalim]

I like Dynamo's functionality of navigating stacktraces, we should definitely work on its functionalities though. I think we should add most of this directly to Plug.

[chrismccord]

@slogson we'd love help. @josevalim, how do you see this being implemented in Plug wrt to file serving/assets? It would be very easy to get in place in Phoenix since we can just render a Phoenix eex template right in the Phoenix ErrorController, i.e. https://github.com/phoenixframework/phoenix/blob/master/lib/phoenix/controller/error_controller.ex#L37

Instead of that placeholder html, we would just render an error_debug.html.eex template with the pretty error stacktraces.

[josevalim]

It will be just a plug. We don't need to worry about assets in the error page as we can always embed them in the html.

[chrismccord]

It will be just a plug. We don't need to worry about assets in the error page as we can always embed them in the html.

👍 we can just call it from the error_debug action. @slogsdon if you want to put together a PR for plug I'll leave this open until we have things in place on the Plug side

[chrismccord]

@slogsdon Have you started on this yet? @gjaldon this would be a good one to tackle if it's still up for grabs.

[gjaldon]

@chrismccord cool! I'd gladly work on this if it is still available! Just to clarify, this will be done in Plug and then add it to the plug stack in Pheonix?

[chrismccord]

Just to clarify, this will be done in Plug and then add it to the plug stack in Pheonix?

Yes, exactly. Let's wait to see where @slogsdon is at. Otherwise, it's all yours!

[slogsdon]

I've started, but I haven't gotten far, to be honest. @gjaldon feel free to pick this up if you're wanting to do so.

[gjaldon]

@slogsdon, great! I'll be taking this on then. 👍

[josevalim]

I am working on this and it will be pushed soon.