diff --git a/src/main/kotlin/day01/Day01.kt b/src/main/kotlin/day01/day01.kt
similarity index 100%
rename from src/main/kotlin/day01/Day01.kt
rename to src/main/kotlin/day01/day01.kt
diff --git a/src/main/kotlin/day02/day02.kt b/src/main/kotlin/day02/day02.kt
new file mode 100644
index 0000000..2a33168
--- /dev/null
+++ b/src/main/kotlin/day02/day02.kt
@@ -0,0 +1,22 @@
+package day02
+
+import java.io.File
+
+const val RED_CUBES = 12
+const val GREEN_CUBES = 13
+const val BLUE_CUBES = 14
+
+val input = File("src/main/kotlin/day02/input.txt").readLines()
+
+fun solve1() = part1(input)
+
+fun solve2() = part2(input)
+
+fun part1(input: List<String>): Int =
+    input.map { line -> Game.parse(line) }
+        .filter { it.isPossible }
+        .sumOf { it.id }
+
+fun part2(input: List<String>): Int =
+    input.map { Game.parse(it) }
+        .sumOf { it.power }
diff --git a/src/main/kotlin/day02/main.kt b/src/main/kotlin/day02/main.kt
deleted file mode 100644
index 88ccf88..0000000
--- a/src/main/kotlin/day02/main.kt
+++ /dev/null
@@ -1,23 +0,0 @@
-package day02
-
-import java.io.File
-
-const val RED_CUBES = 12
-const val GREEN_CUBES = 13
-const val BLUE_CUBES = 14
-
-fun main() {
-    val input = File("src/main/kotlin/day02/input.txt").readLines()
-
-    fun part1(): Int =
-        input.map { line -> Game.parse(line) }
-            .filter { it.isPossible }
-            .sumOf { it.id }
-
-    fun part2(): Int =
-        input.map { Game.parse(it) }
-            .sumOf { it.power }
-
-    println("Day 02, Part 1: ${part1()}")
-    println("Day 02, Part 2: ${part2()}")
-}
diff --git a/src/test/kotlin/day02/Day02Tests.kt b/src/test/kotlin/day02/Day02Tests.kt
new file mode 100644
index 0000000..e59be5a
--- /dev/null
+++ b/src/test/kotlin/day02/Day02Tests.kt
@@ -0,0 +1,52 @@
+package day02
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+
+class Day02Tests {
+    @Test
+    fun `part1 example`() {
+        // arrange
+        val input = listOf(
+            "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green",
+            "Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue",
+            "Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red",
+            "Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red",
+            "Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
+        )
+
+        // act
+        val actual = part1(input)
+
+        // assert
+        assertEquals(8, actual)
+    }
+
+    @Test
+    fun `part1 solution`() {
+        assertEquals(2348, solve1())
+    }
+
+    @Test
+    fun `part2 example`() {
+        // arrange
+        val input = listOf(
+            "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green",
+            "Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue",
+            "Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red",
+            "Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red",
+            "Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
+        )
+
+        // act
+        val actual = part2(input)
+
+        // assert
+        assertEquals(2286, actual)
+    }
+
+    @Test
+    fun `part2 solution`() {
+        assertEquals(76008, solve2())
+    }
+}