determine-test-clientid.js

ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");

const ENABLE_PROB = 0.01;
const ADDON_ID = "...";

XPCOMUtils.defineLazyServiceGetters(this, {
  uuidGen: ["@mozilla.org/uuid-generator;1", "nsIUUIDGenerator"],
});

async function generateVariate(seed, label) {
  const hasher = crypto.subtle;
  const hash = await hasher.digest("SHA-256", new TextEncoder("utf-8").encode(seed + label));
  let view = new DataView(hash);
  return view.getUint32(0) / 0xffffffff;
}

(function loop() {
    uuid = uuidGen.generateUUID().number;
    uuid = uuid.substring(1, uuid.length - 1);
    generateVariate(uuid, ADDON_ID).then(a => {
        if (a < ENABLE_PROB) {
            console.log(`Found one: ${uuid}`);
        } else {
            loop();
        }
    });
})();