Kevin Powell - Community•2mo ago

web extension fetch problem with firefox

Hi all, i just finished a tiny chrome extension, and wanted to post it for firefox too. the extension has only a popup page, and performs a simple fetch() request on a youtube account name (I.E. https://www.youtube.com/@anyAccountName) on firefox, i got a CORS problem. usually, i can solve the problem by adding headers. but i can't solve this one... The fun part, is that a fetch request on https://www.youtube.com works fine here is the manifest

{
    "manifest_version": 3,
    "author" : "me",
    "name": "YT",
    "description": "super description",
    "version": "1.0",
    "icons" : {
       "48" : "img/icon-48.png",
       "64" : "img/icon-64.png",
       "128" : "img/icon-128.png"
    },
    "host_permissions":[
       "https://*.youtube.com/*"
    ],
    "action": {
       "default_icon": "img/icon-48.png",
       "default_popup": "popup.html"
    }
}

{
    "manifest_version": 3,
    "author" : "me",
    "name": "YT",
    "description": "super description",
    "version": "1.0",
    "icons" : {
       "48" : "img/icon-48.png",
       "64" : "img/icon-64.png",
       "128" : "img/icon-128.png"
    },
    "host_permissions":[
       "https://*.youtube.com/*"
    ],
    "action": {
       "default_icon": "img/icon-48.png",
       "default_popup": "popup.html"
    }
}

and here is the popup.js

/* works fine */
fetch('https://www.youtube.com/');

/* fails (i tried multiple options) */
fetch(`https://www.youtube.com/@anyAccoundName`,{
        mode: 'no-cors',
        redirect: 'follow',
        credentials: 'include',
        referrerPolicy: 'no-referrer',
        headers:new Headers({
            'User-Agent': navigator.userAgent,
            'Referer': 'https://www.youtube.com/'
        })
    });

/* works fine */
fetch('https://www.youtube.com/');

/* fails (i tried multiple options) */
fetch(`https://www.youtube.com/@anyAccoundName`,{
        mode: 'no-cors',
        redirect: 'follow',
        credentials: 'include',
        referrerPolicy: 'no-referrer',
        headers:new Headers({
            'User-Agent': navigator.userAgent,
            'Referer': 'https://www.youtube.com/'
        })
    });

any help would be appreciated :/

4 Replies

clevermissfox•2mo ago

Check Firefox setting content.cors.disable preference in about:config

DoksuriOP•2mo ago

content.cors.disable = false if a user installs the exetension, i can't ask him to change his config... but my real interrogation is why does it work on youtube.com, but not on youtube.com/... ?

clevermissfox•2mo ago

Oh I thought this was for your own use. Not sure since you have .com/* could try to use regex in the js file and see if that works any better

DoksuriOP•2mo ago

what ? i think you didn't understand the problem my web extension works perfectly on chrome but not on firefox when debugging, i found that my fetch request on https://www.youtube.com/@example failed and had CORS problem when testing a fetch request on https://www.youtube.com/ the request works fine i can't figure that one out :/

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web extension fetch problem with firefox