New exception page.

[alex-oleshkevich]

This PR updates debugger UI.

Features:

• code preview
• local variables for snippet
• request/session/headers/etc details
• beautify UI
• responsible

UI is influenced by the Phoenix Framework error page

[Kludex]

Beautiful. 👍

[alex-oleshkevich]

Here is a full page screenshot with all sections open.

[alex-oleshkevich]

This handler may raise an exception if one of locals is QuerystringParser.
The bug itself is here Kludex/python-multipart#29, seems fixed but no new version has been released for a long time.

[aminalaee]

This is nice.

[aminalaee]

Suggested change

	if any(
	[
	"key" in key,
	"token" in key,
	"password" in key,
	"secret" in key,
	]
	):
	if any(k in key for k in ["key", "token", "password", "secret"]):

Is this less readable? What do you think?

[aminalaee]

I haven't really checked any other projects, but do you think it would be useful to mask a part of the value? For example masking first half of the string? Or at least mask the length of the value, as I think this might be confusing.

[tomchristie]

This looks fantastic.
Having said that it's also an awful lot of extra code to pull into the core package and maintain.

Presumably you'd also be able to package this up as a third party package, and document how to install it as a custom exception handler, right? (Or are there any blockers there that I've not figured out?)

A good rule of thumb for proposals to Starlette should probably be "if it can be a third party package, it should be".

That's worked really well for REST framework, and it'd work really well for Starlette too - help make sure we can just keep it small and well-scoped, but still allow folks to build fantastic stuff on top of it.

[alex-oleshkevich]

Yes, I have the same thought.

[alex-oleshkevich]

Available as https://github.com/alex-oleshkevich/starception

[tomchristie]

Fantastic stuff.
Want to issue a pull request linking to it from https://www.starlette.io/exceptions/ and https://www.starlette.io/third-party-packages/ ?