webext-active-tab/distribution/tracker.js

WebExtension module: Track `activeTab` permission; automatically inject content scripts

import { isScriptableUrl } from 'webext-content-scripts';
import { isBackground } from 'webext-detect';
import SimpleEventTarget from 'simple-event-target';
if (!isBackground()) {
    throw new Error('This module is only allowed in a background script');
}
const newActiveTabs = new SimpleEventTarget();
const browserAction = chrome.action ?? chrome.browserAction;
// TODO: use webext-storage
export const possiblyActiveTabs = new Map();
async function addIfScriptable({ url, id }) {
    if (id && url
        // Skip if it already exists. A previous change of origin already cleared this
        && !possiblyActiveTabs.has(id)
        // ActiveTab doesn't make sense on non-scriptable URLs as they generally don't have scriptable frames
        && isScriptableUrl(url)
    // Note: Do not filter by `isContentScriptRegistered`; `active-tab` also applies to random `executeScript` calls
    ) {
        const { origin } = new URL(url);
        console.debug('activeTab:', id, 'added', { origin });
        possiblyActiveTabs.set(id, origin);
        newActiveTabs.emit({ id, origin });
    }
    else {
        console.debug('activeTab:', id, 'not added', { origin });
    }
}
function dropIfOriginChanged(tabId, { url }) {
    if (url && possiblyActiveTabs.has(tabId)) {
        const { origin } = new URL(url);
        if (possiblyActiveTabs.get(tabId) !== origin) {
            console.debug('activeTab:', tabId, 'removed because origin changed from', possiblyActiveTabs.get(tabId), 'to', origin);
            possiblyActiveTabs.delete(tabId);
        }
    }
}
function altListener(_, tab) {
    if (tab) {
        void addIfScriptable(tab);
    }
}
function drop(tabId) {
    console.debug('activeTab:', tabId, 'removed');
    possiblyActiveTabs.delete(tabId);
}
// https://developer.chrome.com/docs/extensions/mv3/manifest/activeTab/#invoking-activeTab
export function startActiveTabTracking() {
    browserAction?.onClicked.addListener(addIfScriptable);
    chrome.contextMenus?.onClicked.addListener(altListener);
    chrome.commands?.onCommand.addListener(altListener);
    chrome.tabs.onUpdated.addListener(dropIfOriginChanged);
    chrome.tabs.onRemoved.addListener(drop);
}
export function stopActiveTabTracking() {
    browserAction?.onClicked.removeListener(addIfScriptable);
    chrome.contextMenus?.onClicked.removeListener(altListener);
    chrome.commands?.onCommand.removeListener(altListener);
    chrome.tabs.onUpdated.removeListener(dropIfOriginChanged);
    chrome.tabs.onRemoved.removeListener(drop);
    possiblyActiveTabs.clear();
}
export function addActiveTabListener(callback) {
    startActiveTabTracking();
    newActiveTabs.listen(callback);
}