Advent of Code 2025

Solving Advent of Code puzzles with TypeScript and Bun.

⇁ Packages

@dsqr/aoc-utils - Input utilities library (published on npm)

@aoc/2025 - 2025 puzzle solutions

@aoc/2024 - 2024 puzzle solutions

@aoc/cli - Type-safe CLI framework

⇁ Quick Start

Install dependencies:

bun install

Set your AoC session cookie:

export AOC_SESSION=your_cookie_here

Get your session cookie from https://adventofcode.com (DevTools → Cookies → session)

Run solutions:

# Run all solutions for the year
bun packages/2025/src/index.ts

# Run a single day (both parts)
bun packages/2025/src/day-one/index.ts

# Run a specific part
bun packages/2025/src/day-one/solution-one.ts
bun packages/2025/src/day-one/solution-two.ts

⇁ Was AI used?

Nah, at least not yet lol.

⇁ Create a New Day

bun packages/utils/src/cli/aoc-cli.ts scaffold 2

⇁ Testing

Run all tests with coverage:

bun test --coverage

Watch mode:

bun test --watch

⇁ Build

Build all packages:

bun run build

⇁ Development with Nix

Setup development environment:

nix flake update
direnv allow

This provides Bun, Node.js, and Biome.

⇁ License

Do whatever you want with it. MIT.