aoc-2024/cmd/day_15/main_test.go

package main

import (
	"testing"
)

func TestRobotIsImmobilized(t *testing.T) {
	world := &World{
		width: 3, height: 3,
		wmap: []byte(
			"" +
				"###" +
				"#.#" +
				"###",
		),
	}
	world.robot = indexOf(1, 1, world.width)

	cases := []byte("^v<>")
	for _, c := range cases {
		if world.Robot(c) {
			t.Errorf("Expected nothing to move, but robot moved %q", c)
		}
	}
}

func TestRobotMovesInAllDirections(t *testing.T) {
	world := &World{
		width: 3, height: 3,
		wmap: []byte(
			"" +
				"..." +
				"..." +
				"...",
		),
	}
	center := indexOf(1, 1, world.width)
	cases := []byte("^v<>")
	for _, c := range cases {
		world.robot = center
		if !world.Robot(c) {
			t.Errorf("Expected robot to move %q, but robot did not move", c)
		}
		expected := -1
		switch c {
		case '<':
			expected = center - 1
		case '>':
			expected = center + 1
		case '^':
			expected = center - world.width
		case 'v':
			expected = center + world.width
		}
		actual := world.robot
		if actual != expected {
			actualX, actualY := coordOf(actual, world.width)
			expectedX, expectedY := coordOf(expected, world.width)
			t.Errorf("Expected robot at (%d, %d), but robot was at (%d, %d)",
				expectedX, expectedY,
				actualX, actualY,
			)
		}
	}
}

func TestRobotMovesUntilStoppedByWall(t *testing.T) {
	world := &World{
		width: 6, height: 3,
		wmap: []byte(
			"" +
				"######" +
				"#...##" +
				"######",
		),
	}
	world.robot = indexOf(1, 1, world.width)

	moves := []byte("^v>^v>^v>^v>")
	for _, c := range moves {
		world.Robot(c)
	}
	expected := indexOf(3, 1, 6)
	actual := world.robot
	if actual != expected {
		actualX, actualY := coordOf(actual, world.width)
		expectedX, expectedY := coordOf(expected, world.width)
		t.Errorf("Expected robot at (%d, %d), but robot was at (%d, %d)",
			expectedX, expectedY,
			actualX, actualY,
		)
	}
}