feat: added getRandomItem()

Author: webdeveric

src/getRandomItem.ts

@@ -0,0 +1,16 @@
+import { randomInt } from './randomInt.js';
+
+export function getRandomItem(input: []): undefined;
+
+export function getRandomItem<T>(input: [T, ...T[]]): T;
+
+export function getRandomItem<T>(input: T[]): T | undefined {
+  switch (input.length) {
+    case 0:
+      return;
+    case 1:
+      return input[0];
+    default:
+      return input[randomInt(0, input.length)];
+  }
+}

test/getRandomItem.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest';
+
+import { getRandomItem } from '../src/getRandomItem.js';
+
+describe('getRandomItem()', () => {
+  it('Returns a random item from an array', () => {
+    expect(getRandomItem([1])).toEqual(1);
+
+    expect(getRandomItem([1, 2, 3])).toBeTypeOf('number');
+  });
+
+  it('Returns undefined when input is empty', () => {
+    expect(getRandomItem([])).toBeUndefined();
+  });
+});