Refactor browserID handling. Force retaining browserID on logout

js/plugin/browserID.ts

@@ -0,0 +1,47 @@
+const ID_STORAGE_KEY = "browser_mod-browser-id";
+
+export const BrowserIDMixin = (SuperClass) => {
+  return class BrowserIDMixinClass extends SuperClass {
+    constructor() {
+      super();
+
+      if (Storage) {
+        if (!Storage.prototype.browser_mod_patched) {
+          const _clear = Storage.prototype.clear;
+          Storage.prototype.clear = function () {
+            const browserId = this.getItem(ID_STORAGE_KEY);
+            const suspendWhenHidden = this.getItem("suspendWhenHidden");
+            _clear.apply(this);
+            this.setItem(ID_STORAGE_KEY, browserId);
+            this.setItem("suspendWhenHidden", suspendWhenHidden);
+          };
+          Storage.prototype.browser_mod_patched = true;
+        }
+      }
+    }
+
+    get browserID() {
+      if (localStorage[ID_STORAGE_KEY]) return localStorage[ID_STORAGE_KEY];
+      this.browserID = "";
+      return this.browserID;
+    }
+    set browserID(id) {
+      function _createBrowserID() {
+        const s4 = () => {
+          return Math.floor((1 + Math.random()) * 100000)
+            .toString(16)
+            .substring(1);
+        };
+        return window.fully?.getDeviceId() ?? `${s4()}${s4()}-${s4()}${s4()}`;
+      }
+
+      if (id === "") id = _createBrowserID();
+      const oldID = localStorage[ID_STORAGE_KEY];
+      localStorage[ID_STORAGE_KEY] = id;
+
+      this.browserIDChanged(oldID, id);
+    }
+
+    protected browserIDChanged(oldID, newID) {}
+  };
+};