Cannot install from URLs that end with .user.css in Stylus for Firefox(v57) (works ok in Stylus for Chrome)

[darkred]

First of all, I'm so glad I've found Stylus, it's so much better than Stylish!
Thanks to all for your awesome work!

---

Just one thing:
in the v1.1.4.3 changelog (and in documentation and #134 ), i've read that:

5. [UserCSS mode] Stylus can install from URLs that end with .user.css or .user.styl.

Unfortunately, all .user.css files I tried in Stylus 1.1.6.1 for Firefox (GitHub/gist raw URLs),
only display the CSS code.
Example URLs I've tried:
https://raw.githubusercontent.com/Mottie/Darker-Medium/master/darker-medium.user.css
https://gist.githubusercontent.com/eight04/1b9edeb170d9f8bbabfb06dc6627f8f7/raw/foo.user.css

(In Stylus 1.1.6.1 for Chrome 62, with default settings as well, they all install ok.)

• Browser: Firefox 57 (even in fresh profile), Stylus 1.1.6.1 with default settings
• Operating System: win10 x64
• Screenshot: 2017-11-24_035437

[mechalynx]

In order for Stylus to recognize that it's a .css file in the first place and actually know to parse it (as opposed to a regular text file), it has to be served with the proper mime-type. GitHub's raw display doesn't do that, on either the main site or Gist. In other words, this is a server issue but not a bug on either side.

If you want to install automatically you need to access the file through Rawgit or a similar service that serves the file with the proper mime-type (as text/css).

In the previous links, replace *.githubusercontent.com with rawgit.com and they'll work.

[darkred]

Thank you very much for the quick answer! So, I just installed them.

It's just strange that in Stylus for Chrome, those initial *.githubusercontent.com URLs work:
each one opens 2 tabs, one with the CSS code, and the other with the prompt page to install it.

[mechalynx]

The policies behind Chrome and Firefox's behavior differ. Chrome is built in such a way that it is more aggressive in what it assumes the user wants. This works ok sometimes (like this case) and in other cases backfires and causes problems. Firefox prefers standardized behavior and consistency, which also has its ups and downs.

In any case, there is a solution that works for both in this situation and I'll be updating the wiki to make sure this is clear in the future. Thanks for using user.css!

[Mottie]

When @eight04 developed the user.css installer, it was made to work with *.githubusercontent.com source files. I'm not sure why @darkred was having trouble, but both links work fine for me in Chrome for Windows 10 x64. Did you see any console errors?

Also, please check the console of the background page. Click the following link seen on the chrome://extensions/ page.

[mechalynx]

@Mottie works in Chrome fine, just not in Firefox.

[Mottie]

Ahhh derp, I guess I should learn to read... LOL

[eight04]

I'm pretty sure it is a CSP bug in Firefox.
greasemonkey/greasemonkey#2631

No content script can be injected into those pages.

[tophf]

For those who randomly found this issue: Stylus added a workaround for githubusercontent.com using a webNavigation API listener.