Day 2: Sum calculation in program

src/main/kotlin/day2/Day2.kt

@@ -4,9 +4,15 @@ import java.io.File
 
 object Day2 {
 
-    fun readGames(file: File = File("src/main/resources/day2/input.txt")): List<Game> = file
-        .readLines()
-        .map(Game.Companion::parse)
+    fun sumOfCompatibleGames(hand: Hand) = readGames()
+        .filter { it.isCompatibleWith(hand) }
+        .map(Game::id)
+        .sum()
+
+    private fun readGames(): List<Game> =
+        File("src/main/resources/day2/input.txt")
+            .readLines()
+            .map(Game.Companion::parse)
 
 }
 

src/test/kotlin/day2/Day2Test.kt

@@ -6,10 +6,6 @@ class Day2Test {
 
     @Test
     fun readGames() {
-        val compatibleGames = Day2.readGames().filter { game ->
-            Hand(12, 13, 14).let(game::isCompatibleWith)
-        }
-
-        assert(compatibleGames.map(Game::id).joinToString(separator=",") == "1,2,5")
+        assert(Day2.sumOfCompatibleGames(Hand(12, 13, 14)) == 8)
     }
 }