feat: implement new median function

src/index.js

@@ -15,6 +15,18 @@ export function sum(values) {
 export function average(values) {
   return sum(values) / values.length;
 }
+/**
+ * Calculated median average of all numbers in array.
+ * @param {number[]} values Numbers to average.
+ * @returns {number} Median of all numbers.
+ */
+export function median(values) {
+  const sorted = sort(values, 'asc');
+  if (sorted.length % 2 === 0) {
+    return average([sorted[sorted.length / 2 - 1], sorted[sorted.length / 2]]);
+  }
+  return sorted[Math.floor(sorted.length / 2)];
+}
 
 /**
  * Sort array by numeric values.

test/index.test.js

@@ -1,6 +1,6 @@
 import assert from 'node:assert';
 import { describe, it } from 'node:test';
-import { average, sort, sum } from '../src/index.js';
+import { average, median, sort, sum } from '../src/index.js';
 
 describe('sum', () => {
   it('should sum all numbers', () => {
@@ -18,6 +18,16 @@ describe('average', () => {
   });
 });
 
+describe('median', () => {
+  it('should calculate median for odd-length array', () => {
+    assert.strictEqual(median([3, 1, 2]), 2);
+  });
+
+  it('should calculate median for even-length array', () => {
+    assert.strictEqual(median([3, 4, 1, 2]), 2.5);
+  });
+});
+
 describe('sort', () => {
   it('should sort numbers in ascending order by default', () => {
     assert.deepEqual(sort([4, 2, 1, 3]), [1, 2, 3, 4]);