1888742 - Couldn't load extension with background type 'module' in V3 manifest

Status: RESOLVED INVALID

(WebExtensions :: Untriaged, defect)

Description

[ris58h]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:124.0) Gecko/20100101 Firefox/124.0

Steps to reproduce:

I have an extension with background.type.='module' in manifest V3.

Link to the manifest: https://github.com/ris58h/youtube-chapters-in-player/blob/master/extension/manifest.json

Actual results:

There was an error during the temporary add-on installation.
Error details

Extension is invalid

Reading manifest: Error processing background: Value must either: contain the required "page" property, contain the required "scripts" property, or not contain an unexpected "type" property

Expected results:

Extension should be loaded without error as it's done in Chrome.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'WebExtensions::Untriaged' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Alex Cornestean]

Hello,

I reproduced the issue on the latest Nightly (126.0a1/20240331204101), Beta (125.0b6/20240329091918) and Release (124.0.1/20240321230221) under Windows 10 x64 and Ubuntu 22.04 LTS.

Attempting to load the linked manifest in about:debugging will fail with the error mentioned in Comment 0.

Comment 3

[Rob Wu [:robwu]]

The issue with your extension is not type: "module", but the use of service_worker which Firefox does not support yet.

After looking at your extension, there does not seem to be any service-worker specific API, and you should be able to get the extension working in Firefox and Chrome by adding "scripts": ["background/background.js"] in the background key of your manifest.json file. This is documented at https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/background#browser_support

Comment 4

[ris58h]

Maybe there is no service-worker specific API but it was the way to make modules work in Chrome.

Comment 5

[Rob Wu [:robwu]]

type: "module" is supported in Firefox.

Does my suggestion (scripts + service_worker + type':"module") solve your issue?

Comment 6

[ris58h]

I've changed it to

"background": {
    "service_worker": "background/background.js",
    "scripts": ["background/background.js"],
    "type": "module"
},

as you suggested and it just doesn't work. No errors, no logs, nothing.

Comment 7

[Rob Wu [:robwu]]

I created the following test case, which should open a new tab when the extension loads. I can confirm that it works in Firefox 121+ and Chrome 121+.

If there is anything "not working" with your extension, it is unrelated to the "module" or "background" issue that you have reported.

Note: currently, Manifest V3 extensions are not automatically granted host permissions upon install. We're going to change that soon, in bug 1889402.

manifest.json

{
    "name": "module background test",
    "version": "1",
    "manifest_version": 3,
    "background": {
        "service_worker": "background.js",
        "scripts": ["background.js"],
        "type": "module"
    }
}

background.js

import "./hello.js"

hello.js

chrome.tabs.create({ url: "https://example.com/?hello" });