Simplify structure and tests

Author: hsz

src/main/kotlin/com/github/hsz/aoc/Day.kt

@@ -2,11 +2,15 @@ package com.github.hsz.aoc
 
 import com.github.hsz.aoc.utils.Resources
 
-abstract class Day(val number: Number) {
+abstract class Day(number: Number) {
 
-    val input = Resources.asString("day${number.toString().padStart(2, '0')}.txt")
+    private val input = Resources.asString("day${number.toString().padStart(2, '0')}.txt")
 
     abstract fun part1(input: String): Any
 
+    fun part1() = part1(input)
+
     abstract fun part2(input: String): Any
+
+    fun part2() = part2(input)
 }

src/main/kotlin/com/github/hsz/aoc/Day01.kt

@@ -1,6 +1,7 @@
 package com.github.hsz.aoc
 
 class Day01 : Day(1) {
+
     override fun part1(input: String): Int {
         return 0
     }

src/main/kotlin/com/github/hsz/aoc/utils/utils.kt

@@ -1,11 +1,14 @@
-package com.github.hsz.aoc
+package com.github.hsz.aoc.utils
+
+import java.math.BigInteger
+import java.security.MessageDigest
 
 /**
  * Maps a string containing integers in new lines to a list of integers.
  */
-fun String.ints(): List<Int> = lines().map(String::toInt)
+fun String.ints() = lines().map(String::toInt)
 
 /**
- * Shorthand for [String.toInt].
+ * Converts string to md5 hash.
  */
-operator fun String.unaryPlus() = toInt()
+fun String.md5(): String = BigInteger(1, MessageDigest.getInstance("MD5").digest(toByteArray())).toString(16)

src/test/kotlin/com/github/hsz/aoc/Day01Test.kt

@@ -3,15 +3,19 @@ package com.github.hsz.aoc
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
-class Day01Test : DayTest(Day01()) {
+class Day01Test : DayTest() {
+
+    override val day = Day01()
+
     @Test
     fun part1() {
-        assertEquals(0, day.part1(""))
+        assertEquals(0, day.part1("foo")) // check against test input
+        assertEquals(0, day.part1()) // check against input data
     }
 
     @Test
     fun part2() {
-        assertEquals(0, day.part2(""))
-        assertEquals(0, day.part2(day.input))
+        assertEquals(0, day.part2("bar"))
+        assertEquals(0, day.part2())
     }
 }

src/test/kotlin/com/github/hsz/aoc/DayTest.kt

@@ -3,14 +3,7 @@ package com.github.hsz.aoc
 import org.junit.jupiter.api.AfterAll
 import org.junit.jupiter.api.TestInstance
 
-@TestInstance(TestInstance.Lifecycle.PER_CLASS)
-abstract class DayTest(val day: Day) {
-    @AfterAll
-    fun solve() {
-        with(day) {
-            println("Solutions for Day $number:")
-            println("Part 1: ${part1(input)}")
-            println("Part 2: ${part2(input)}")
-        }
-    }
+abstract class DayTest {
+
+    abstract val day: Day
 }