Script Injection

content.js

const _addEventListener = addEventListener

EventTarget.prototype.addEventListener = function (type, listener) {
    switch (type) {
        case 'visibilitychange':
            _addEventListener.apply(this, [
                type,
                () => console.log(`${type} is disabled`)
            ])
            break
        default:
            console.log(`${type} is enabled`)
            _addEventListener.apply(this, arguments)
            break
    }
}

main.js

// inject script
const script = document.createElement("script");
script.src = chrome.runtime.getURL("js/content.js");
(document.head || document.documentElement).insertAdjacentElement('afterbegin', script)

manifest.json

{
    "name": "__MSG_appName__",
    "version": "0.1",
    "manifest_version": 3,
    "description": "__MSG_appDesc__",
    "default_locale": "ja",
    "icons": {
        "128": "img/icon_128.png"
    },
    "content_scripts": [
        {
            "matches": [
                "https://google.com/*"
            ],
            "js": [
                "js/main.js"
            ],
            "run_at": "document_start"
        }
    ],
    "web_accessible_resources": [
        {
            "resources": [
                "js/*"
            ],
            "matches": [
                "<all_urls>"
            ]
        }
    ],
    "offline_enabled": true
}