| Day | Title | Code | Tests | Tags |
|---|---|---|---|---|
| Day 1 | Not Quite Lisp | code | tests | parentheses counts |
| Day 2 | I Was Told There Would Be No Math | code | tests | gifts; perimeter; area; volume |
| Day 3 | Perfectly Spherical Houses in a Vacuum | code | tests | path; repeated stops; santa delivers gifts |
| Day 4 | The Ideal Stocking Stuffer | code | tests | md5; repetitions; prefix |
| Day 5 | Doesn't He Have Intern-Elves For This? | code | tests | regex; string validation |
| Day 6 | Probably a Fire Hazard | code | tests | light status; switch on and off |
| Day 7 | Some Assembly Required | code | tests | bitwise operations; chain |
| Day 8 | Matchsticks | code | tests | strings; string literals; char count |
| Day 9 | All in a Single Night | code | tests | shortest trip; permutations |
| Day 10 | Elves Look, Elves Say | code | tests | look-and-say; 11 = 21 ("two 1s") |
| Day 11 | Corporate Policy | code | tests | password; validation rules; regex |
| Day 12 | JSAbacusFramework.io | code | tests | read json recursively |
| Day 13 | Knights of the Dinner Table | code | tests | permutations; people circle; happiness |
| Day 14 | Reindeer Olympics | code | tests | reindeer race |
| Day 15 | Science for Hungry People | code | tests | ingredients; combinations; calories count |
| Day 16 | Aunt Sue | code | tests | simply aunt Sue |
| Day 17 | No Such Thing as Too Much | code | tests | containers; combinations of diff sizes |
| Day 18 | Like a GIF For Your Yard | code | tests | game of life; lights; stuck corners |
| Day 19 | Medicine for Rudolph | code | tests | string replacements; recursion; tailrec |
| Day 20 | Infinite Elves and Infinite Houses | code | tests | factors; modules |
| Day 21 | RPG Simulator 20XX | code | tests | player vs boss; turns |
| Day 22 | Wizard Simulator 20XX | code | tests | wizard vs boss; turns |
| Day 23 | Opening the Turing Lock | code | tests | instructions; registers; offsets |
| Day 24 | It Hangs in the Balance | code | tests | numbers; combinations |
| Day 25 | Let it snow | code | tests | grid of increasing numbers; module; Gauss |