import from up to date repo

client/src/utility/array.ts

@@ -0,0 +1,17 @@
+export const arrayPartition = <T>(
+  arr: T[],
+  isValid: (e: T) => boolean
+): T[][] => {
+  let pass: T[] = [];
+  let fail: T[] = [];
+
+  arr.forEach((e) => (isValid(e) ? pass : fail).push(e));
+
+  return [pass, fail];
+};
+
+export const insertAt = <T>(arr: T[], index: number, element: T): T[] => [
+  ...arr.slice(0, index),
+  element,
+  ...arr.slice(index + 1),
+];