Bug 213215 – Web Inspector: CORS preflight OPTIONS requests no longer shown in Network tab

• Component: Web Inspector
• Status: RESOLVED DUPLICATE

[sideshowbarker]

See https://stackoverflow.com/questions/60290892/safari-cors-options-preflight-requests-not-showing-in-dev-tools for a user report about Web Inspector no longer displaying CORS preflight OPTIONS requests in the Network tab.

[Radar WebKit Bug Importer]

<rdar://problem/64383719>

[Brock Mills]

Created attachment 401974 [details]
web inspector screen shot

[Brock Mills]

This happens using Version 13.1.1 (15609.2.9.1.2) on Catalina, first time I noticed it was early Jan.

Attached screen shot shows the web inspector network tab with a POST that used CORS OPTIONS pre-flight. This request is not shown in the network tab.

[Karen]

Please re-establish the ability to see preflight CORS OPTION requests for cached images in Safari inspector.

The inability to debug those calls is impacting troubleshooting Safari's current odd CORS error for CACHED resources like images sources that are redirects. (i.e. Canvas Instructure image src redirect to AWS S3, when cached by Safari.)
Since it's https calls, wireshark can't easily get the Safari signatures used on the https CORS OPTIONS menthod.

Example of the issue that cannot be easily debugged:
1. In Safari latest v13, Go to site https://cidilabs.instructure.com/courses/3/pages/upload-slash-embed-image-test
2. Then refresh that page to see the broken image link.

Some unsatisfactory workaround Options because the Safari CORS cache methods can't be debugged:
- Use a private Safari browser when going to a CORS redirect image page. The issue only happens when the image is cached.
- Add a terminating solidus (forward slash) to all image src links that are cached CORS redirect paths. The issue only happens when the redirect path looks like a file not a directory.
- Make the image src URL a DIFFERENT host than the page it's embedded in. The issue only happens if the cached image src redirect URL is the *same* host as the web page.
- Use FireFox or Chrome when  going to a page with a CORS image src redirect. The issue only happens with Safari.

Ref https://stackoverflow.com/questions/63141448/safari-fetch-api-cannot-load-due-to-access-control-checks-after-reload/63850653#63850653

[Marcos G.]

This would be really useful for debugging.

[Chris F Carroll]

I don't see Vote option in Bugzilla so: +1
thankyou. Chris

[Ryan Bagwell]

+1 for this. very frustrating devtools doesn't log OPTIONS requests.

This feature has been missing since at least Safari 11

[Bert Goethals]

It's 2022 and this still is not possible. 

Would be really great to get this working!

[tpak]

+1 this is extremely frustrating to try and debug our application with Safari users - this should not be a thing in 2022 that developers can't debug webapps properly

[Kito D. Mann]

+1 Debugging with Chrome DevTools is infinitely easier. This shouldn't be a problem in 2022!

[Micah]

+1 Please prioritize this. It's essential to debugging CORS issues in Safari. I'm having to recommend that our internal users use Chrome b/c I'm unable to fix CORS bugs that only show up in Safari and have no way of triaging them.

[Sam Sneddon [:gsnedders]]

Does anyone have any evidence of this having previously worked?

*** This bug has been marked as a duplicate of bug 164889 ***