CORS being too strict and blocking localhost resources

[ipontt]

I am experiencing the bug described in https://bugzilla.mozilla.org/show_bug.cgi?id=1376310 with the latest version of firedragon. It's fix also worked (using [::1] instead of localhost or 127.0.0.1).

According to this bug report, it's been fixed in firefox 75. Has the version of librewolf firedragon is based on implemented this fix?

[dr460nf1r3]

Hum, this should be available as we use Firefox as source. Maybe its another bug with common symptoms?

[ipontt]

I'm asking because I tried following a free course that used this repo as a base but ran into the weird error. The steps I took were the following:

1. git clone https://github.com/Code-Pop/from-vuex-to-pinia.git
2. cd into the directory
3. Go into the branch I wanted to work on git switch 03-Begin
4. Install npm dependencies with npm i
5. run command npm run dev as defined in its package.json file
6. Try to open the site at localhost:8080 and the "db" at localhost:3000

This is the definition of the dev command

"vite & json-server --watch db.json"

vite serves the site on localhost:8080 and json-server makes the db.json file available as a mini json api on localhost:3000.

The thing is, localhost:3000 didn't work. The connection was just refused. I tried all sorts of voodoo fixes but the only one that worked (and provided some explanation for it) was the one I linked above.

http://localhost:3000 didn't work.
http://[::1]:3000 did.

I haven't really changed things in about:config and I updated just yesterday (currently on 111.0).

[dr460nf1r3]

Thanks for the instructions on how to reproduce it!

[dr460nf1r3]

Would you be so kind to test whether this also happens on Librewolf? It would help tracking down whether this is an actual FireDragon issue.

[ipontt]

I have just tried it on librewolf. The issue was not present.

This is a comparison between two windows of firedragon, as well as firedragon's version.