Make sure you have node version 20+ installed. (I recommend using asdf to manage your node versions if you need to maintain an older version of node).
To write the solutions for the puzzles use the node test runner:
# runs the tests for day 1 and watches for changes. Change the day number to run the tests for a different day.
node --test --watch --test-name-pattern="day 1"The tests are written in ./src/test/day-<day>.test.mjs. The solutions are written in ./src/day-<day>/part1.mjs and ./src/day-<day>/part2.mjs.
Once you are happy with your solution you can run the puzzle input through it:
# finds the solution for day 1
node src/day-01/main.mjssrc/day-01/main.mjs is a wrapper around your solution that reads the puzzle input from src/day-01/input.txt and prints the solution to the console.
To work on any other day just duplicate the src/day-01 folder and rename it to the day you want to work on, you will also need to duplicate the test file and provide the correct input under input.txt.