1445635 - Display a message when a resource fetch has been rejected because of CORS

Status: NEW

(Core :: Networking: HTTP, enhancement, P5)

Description

[Julien Wajsberg [:julienw]]

Attachment: chrome's error message

When some resource fetch fails because of CORS, we have an error on the JS side that is "NetworkError when attempting to fetch resource." and nothing more to help debugging.

Chrome displays a nice error in the console (see attachment), we should have something similar.

Comment 1

[Brian Grinstead [:bgrins]]

Christoph, do you have an idea how to update the message to be more clear that it failed because of CORS?

Comment 2

[Thomas Wisniewski]

It would also be helpful to provide a stack trace for the code which initiated the fetch, where possible/applicable.

Comment 3

[Christoph Kerschbaumer [:ckerschb]]

(In reply to Brian Grinstead [:bgrins] from comment #1)
> Christoph, do you have an idea how to update the message to be more clear
> that it failed because of CORS?

In fact, vino is working on it, see:
  https://bugzilla.mozilla.org/show_bug.cgi?id=1442551#c5
Should land within this cycle.

Comment 4

[Julien Wajsberg [:julienw]]

> Christoph, do you have an idea how to update the message to be more clear that it failed because of CORS?

Just to be clear, the NetworkError we get is at the "fetch" call site. That it's shown in the console depends on the code. I think it would be a good idea to unconditionally show an error in the console like Chrome does.