Simple Suspender by VehpuS

Background
==========
My own TL;DR
--------------------

The great suspender was an extension that would automatically replace an open tab with a static, low memory page that would redirect back to the original on demand or after a set idle time. After a change of ownership, it was abused to contain malware, and therefore removed by Google.

Looking to avoid another extension by an unknown developer (who can always change), I opted to find a safer solution. I believe I have found it and want to share it in a way that can let others use / replicate it for their own benefit, at the level of knowledge and safety they require.

Additional resources
------------------------------
The great suspender (RIP): https://www.zdnet.com/article/google-kills-the-great-suspender-heres-what-you-should-do-next/

In much more detail: https://github.com/greatsuspender/thegreatsuspender/issues/1263

Why is this solution safer
=====================
No static page - cannot be abused without changing the logic in a noticeable way.

Hash parameter - not sent to a server by the browser, by design.
https://stackoverflow.com/questions/15238391/hash-params-vs-url-params-when-to-use-which

I decided to use localhost:0 as a "host" to keep things local, and on a port that shouldn't conflict with other services / local servers.
See why here: https://www.lifewire.com/port-0-in-tcp-and-udp-818145

Simple code base - easy to fork, install manually, and if necessary - replicate.

The core of the script boils down to:

const suspendPrefix = "https://localhost:0/#";
const toggleSuspendUrl = (pageUrl) =>
pageUrl.startsWith(suspendPrefix)
? pageUrl.replace(suspendPrefix, "")
: `${suspendPrefix}${pageUrl}`;
if (browser) {
browser.browserAction.onClicked.addListener((tab) => {
browser.tabs.update(tab.id, { url: toggleSuspendUrl(tab.url) });
});
}

The API I'm using doesn't require running Javascript code on the web page in the tab - just to get a page's URL. This makes the abuse potential minimal, and is reflected in the extensions limited permissions.

Advanced features, if/when added, will be "opt in" via a separate installation (on stores if / when I upload them) and branch (or possibly repository) - to always provide a stable, simple, and secure base version.

Known issues
===========
Cannot unsuspend internal pages in Firefox, due to the following issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1269456