fix: #397 #373 Array.prototype.at polyfill errors

app/polyfill.ts

@@ -0,0 +1,27 @@
+declare global {
+  interface Array<T> {
+    at(index: number): T | undefined;
+  }
+}
+
+if (!Array.prototype.at) {
+  Array.prototype.at = function (index: number) {
+    // Get the length of the array
+    const length = this.length;
+
+    // Convert negative index to a positive index
+    if (index < 0) {
+      index = length + index;
+    }
+
+    // Return undefined if the index is out of range
+    if (index < 0 || index >= length) {
+      return undefined;
+    }
+
+    // Use Array.prototype.slice method to get value at the specified index
+    return Array.prototype.slice.call(this, index, index + 1)[0];
+  };
+}
+
+export {};