some game joining logic

client/modules/UserUtility.js

@@ -0,0 +1,41 @@
+import { globals } from '../config/globals.js';
+
+export const UserUtility = {
+
+    createNewAnonymousUserId (force = true) {
+        let newId;
+        const currentId = sessionStorage.getItem(globals.PLAYER_ID_COOKIE_KEY);
+        if (currentId !== null && !force) {
+            newId = currentId;
+        } else {
+            newId = createRandomUserId();
+            sessionStorage.setItem(globals.PLAYER_ID_COOKIE_KEY, newId);
+        }
+        return newId;
+    },
+
+    setAnonymousUserId (id) {
+        sessionStorage.setItem(globals.PLAYER_ID_COOKIE_KEY, id);
+    },
+
+    validateAnonUserSignature () {
+        const userSig = sessionStorage.getItem(globals.PLAYER_ID_COOKIE_KEY);
+        return (
+            userSig
+            && typeof userSig === 'string'
+            && /^[a-zA-Z0-9]+$/.test(userSig)
+            && userSig.length === globals.USER_SIGNATURE_LENGTH
+        )
+            ? userSig
+            : false;
+    }
+
+};
+
+function createRandomUserId () {
+    let id = '';
+    for (let i = 0; i < globals.USER_SIGNATURE_LENGTH; i++) {
+        id += globals.ACCESS_CODE_CHAR_POOL[Math.floor(Math.random() * globals.ACCESS_CODE_CHAR_POOL.length)];
+    }
+    return id;
+}