Advent of code "framework"

1_Solver.scala

import scala.util.Using

trait Solver[Day <: Int: ValueOf, Part <: Int: ValueOf]:

  /** Solves the `Part` of the solution for the `Day`
    *
    * @param input
    *   The lines of the input file
    * @return
    *   The solution
    */
  def solve(input: Vector[String]): Int

object Solver:

  def solve[Day <: Int: ValueOf, Part <: Int: ValueOf](using
      solver: Solver[Day, Part],
  ): Unit =
    val input = Using(
      scala.io.Source.fromResource(
        s"inputs/day${valueOf[Day]}.txt",
      ),
    )(_.getLines().toVector).get

    val solution = solver.solve(input)

    println(
      s"Solution to Day ${valueOf[Day]}, part ${valueOf[Part]}: ${solution}",
    )

2_main.scala

@main
def main(): Unit =
  Solver.solve[1, 1]

3_day1.scala

given day1Part1Solution: Solver[1, 1] = new Solver[1, 1]:

  override def solve(input: Vector[String]): Int =
    // no spoilers :)
    -1

given day1Part2Solution: Solver[1, 2] = new Solver[1, 2]:

  override def solve(input: Vector[String]): Int =
    // no spoilers :)
    -1

4_ExampleValidator.scala

import org.scalatest.flatspec.AnyFlatSpec

trait ExampleValidator[Day <: Int: ValueOf](
    part1Solution: Int,
    part2Solution: Int,
)(examples: Vector[String] | (Vector[String], Vector[String]))(using
    Solver[Day, 1],
    Solver[Day, 2],
) extends AnyFlatSpec:

  private type Selector = ((Vector[String], Vector[String])) => Vector[String]

  private def validateExample[Part <: Int: ValueOf](using
      Solver[Day, Part],
  ): Unit = {
    s"Day ${valueOf[Day]}, Part ${valueOf[Part]}" should "produce the correct result for the example" in {
      val (selector, expectedResult): (Selector, Int) =
        valueOf[Part] match
          case 1 => ((_._1): Selector, part1Solution)
          case 2 => ((_._2): Selector, part2Solution)
          case _ => throw Exception(s"Invalid part number: ${valueOf[Part]}")

      val solution = summon[Solver[Day, Part]].solve(
        examples match
          case tuple: (Vector[_], Vector[_]) => selector(tuple)
          case vector: Vector[_]             => vector,
      )

      assert(solution == expectedResult)
    }

  }

  validateExample[1]
  validateExample[2]

5_Day1Test.scala

class Day1Test
    extends ExampleValidator[1](11, 31)(
      Vector(
        "3   4",
        "4   3",
        "2   5",
        "1   3",
        "3   9",
        "3   3",
      ),
    )