chrome.downloads.download() to d/l a file packaged with an extension - google-chrome-extension

Question

System:
Manjaro Linux
Chromium Version 104.0.5112.79 (Official Build) Arch Linux (64-Bit)
When the user clicks on this MV3 extension's action, it tries to download the file /text/Test.txt (packaged with the extension) to the Downloads directory:
https://github.com/GrippenDynamik/Download_Extension_File_MV3
manifest.json
{
"manifest_version": 3,
"name": "Download Extension File MV3",
"version": "1.0",
"action": {
"default_title": "Download Extension File MV3"
},
"background": {
"service_worker": "background.js"
},
"permissions": [
"downloads"
]
}
background.js
function onChanged(downloadDelta) {
console.log("MV3", "b) onChanged", "downloadDelta", downloadDelta);
}
async function onCreated(downloadItem) {
console.log("MV3", "a) onCreated", "downloadItem", downloadItem);
}
function onClicked(tab, onClickData) {
chrome.downloads.download({
conflictAction: "overwrite",
filename: "Test.txt",
saveAs: false,
url: chrome.runtime.getURL("text/Test.txt"),
});
}
chrome.downloads.onChanged.addListener(onChanged);
chrome.downloads.onCreated.addListener(onCreated);
chrome.action.onClicked.addListener(onClicked);
/text/Test.txt
This is a test.
Results:
chrome.downloads.onCreated doesn't report any errors.
chrome.downloads.onChanged reports NETWORK_FAILED (and nothing else)
Am I doing something wrong, or it is not possible to download files packaged with an extension?
I know that I can
fetch() the file
turn the response into a data URL
download the data URL
But it would be nice if I could skip steps 1 and 2.
Simpler is better.

Answer 1

The problem is MV3, as usual.
https://bugs.chromium.org/p/chromium/issues/detail?id=1224027&q=downloads.download&can=2
"it doesn't work with chrome.downloads.download which doesn't support chrome-extension:// scheme"
I don't know if this is by design, or just another MV3 bug.
It works perfectly in MV2:
https://github.com/GrippenDynamik/Download_Extension_File_MV2
manifest.json
{
"manifest_version": 2,
"name": "Download Extension File MV2",
"version": "1.0",
"browser_action": {
"default_title": "Download Extension File MV2"
},
"background": {
"scripts": ["background.js"],
"persistent": false
},
"permissions": [
"downloads"
]
}
background.js
function onChanged(downloadDelta) {
console.log("MV2", "b) onChanged", "downloadDelta", downloadDelta);
}
async function onCreated(downloadItem) {
console.log("MV2", "a) onCreated", "downloadItem", downloadItem);
}
function onClicked(tab, onClickData) {
chrome.downloads.download({
conflictAction: "overwrite",
filename: "Test.txt",
saveAs: false,
url: chrome.runtime.getURL("text/Test.txt"),
});
}
chrome.downloads.onChanged.addListener(onChanged);
chrome.downloads.onCreated.addListener(onCreated);
chrome.browserAction.onClicked.addListener(onClicked);
/text/Test.txt
This is a test.