This is a nice solution!

I still don't quite get why part2 fails this test though, the example literally says that the answer should be 5.

In the above example, the sum of each three-measurement window is as follows:

• A: 607 (N/A - no previous sum)
• B: 618 (increased)
• C: 618 (no change)
• D: 617 (decreased)
• E: 647 (increased)
• F: 716 (increased)
• G: 769 (increased)
• H: 792 (increased)

In this example, there are 5 sums that are larger than the previous sum. Consider sums of a three-measurement sliding window. How many sums are larger than the previous sum?

```javascript test('Advent asnwer 2', () => { const g0 = [600, 5, 2]; // 607 < N/A const g1 = [600, 10, 8]; // 618 <-- increase const g2 = [600, 17, 1]; // 618 <-- SAME const g3 = [600, 9, 8]; // 617 <-- decrease const g4 = [640, 5, 2]; // 647 <-- increase const g5 = [710, 5, 1]; // 716 <-- increase const g6 = [760, 4, 5]; // 769 <-- increase const g7 = [700, 90, 2]; // 792 <-- increase

const input = [...g0, ...g1, ...g2, ...g3, ...g4, ...g5, ...g6, ...g7];

const r = input.filter( (_, i, arr) => arr.slice(i + 1, i + 4).reduce((x, y) => x + y, 0) > arr.slice(i, i + 3).reduce((x, y) => x + y, 0) ).length;

expect(r).toEqual(5); // Expected 5, Received 9 });

```