forgot to add a file

client/shuffle.js

+
+
+// from https://github.com/bryc/code/blob/master/jshash/PRNGs.md#mulberry32
+function mulberry32(a) {
+  return function () {
+    a |= 0; a = a + 0x6D2B79F5 | 0;
+    var t = Math.imul(a ^ a >>> 15, 1 | a);
+    t = t + Math.imul(t ^ t >>> 7, 61 | t) ^ t;
+    return ((t ^ t >>> 14) >>> 0) / 4294967296;
+  }
+}
+
+
+// Fisher–Yates Shuffle
+export default function shuffle(array, seed) {
+  array = [...array];
+  let getRand = mulberry32(seed);
+  let currentIndex = array.length;
+  while (currentIndex != 0) {
+    let randomIndex = Math.floor(getRand() * currentIndex);
+    currentIndex--;
+    // And swap it with the current element.
+    [array[currentIndex], array[randomIndex]] = [
+      array[randomIndex], array[currentIndex]
+    ];
+  }
+  return array;
+}