share data between 2 greasemonkey scripts running on different pages - greasemonkey

Question

with Firefox 68 and Greasemonkey 4.9, i want to set a value from a script on a webpage and get that same value from another script on another webpage. it seems not working. How can i do that ? Here is what i tried :
script 1
// ==UserScript==
// #name My EDIT
// #version 1
// #match http://one.local/stuff/edit*
// #grant GM.setValue
// #grant GM.getValue
// ==/UserScript==
(async () => {
let count = await GM.getValue('count', 0);
await GM.setValue('count', count + 1);
console.log(count);
})();
script 2
// ==UserScript==
// #name My VIEW
// #version 1
// #match http://www.two.local/view
// #grant GM.getValue
// ==/UserScript==
(async () => {
let count = await GM.getValue('count', 0);
console.log(count);
})();
even if values are incremented when i visite http://one.local/stuff/edit many times, i can't get those when visiting http://www.two.local/view (it remains 0 !

Answer 1

Any good script manger should NOT allow script A access script B storage as it would be a serious security breach.
You can combine the scripts into one script, that runs on both pages. That way the storage would be shared.
Simple example:
// ==UserScript==
// #name Combined
// #version 1
// #match http://one.local/stuff/edit*
// #match http://www.two.local/view
// #grant GM.setValue
// #grant GM.getValue
// ==/UserScript==
(async () => {
// code for one.local
if (location.hostname === 'one.local') {
const count = await GM.getValue('count', 0);
await GM.setValue('count', count + 1);
console.log(count);
}
// code for www.two.local
else if (location.hostname === 'www.two.local') {
const count = await GM.getValue('count', 0);
console.log(count);
}
})();