few updates to 99 bottles implementations while prepping for workshop

Author: LarsEckart

src/main/java/lars/katas/bottles/Bottles.java

@@ -1,41 +1,10 @@
 package lars.katas.bottles;
 
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
+public interface Bottles {
 
-public class Bottles {
+  public String verse(int n);
 
-  public String verse(int n) {
-    if (n == 0) {
-      return "No more bottles of beer on the wall, no more bottles of beer.\n"
-          + "Go to the store and buy some more, 99 bottles of beer on the wall.\n";
-    }
+  public String verses(int start, int end);
 
-    String result = "";
-
-    String bottles = n == 1 ? "bottle" : "bottles";
-    result += String.format("%d %s of beer on the wall, %d %s of beer.\n", n, bottles, n, bottles);
-
-    int afterBottleCount = n - 1;
-    String afterBottles = n - 1 == 1 ? "bottle" : "bottles";
-
-    if (afterBottleCount == 0) {
-      result += "Take it down and pass it around, ";
-      result += "no more bottles of beer on the wall.\n";
-    } else {
-      result += "Take one down and pass it around, ";
-      result += String.format("%d %s of beer on the wall.\n", afterBottleCount, afterBottles);
-    }
-    return result;
-  }
-
-  public String verses(int start, int end) {
-    return Stream.iterate(start, i -> i >= end, i -> i - 1)
-        .map(this::verse)
-        .collect(Collectors.joining("\n"));
-  }
-
-  public String song() {
-    return verses(99, 0);
-  }
+  public String song();
 }

src/main/java/lars/katas/bottles/OpenBottles.java

@@ -3,19 +3,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class OpenBottles extends Bottles {
-
-  @Override
-  public String song() {
-    return verses(99, 0);
-  }
-
-  @Override
-  public String verses(int start, int end) {
-    return Stream.iterate(start, i -> i >= end, i -> i - 1)
-        .map(this::verse)
-        .collect(Collectors.joining("\n"));
-  }
+public class OpenBottles implements Bottles {
 
   @Override
   public String verse(int number) {
@@ -30,6 +18,18 @@ public String verse(int number) {
         + " of beer on the wall.\n";
   }
 
+  @Override
+  public String verses(int start, int end) {
+    return Stream.iterate(start, i -> i >= end, i -> i - 1)
+        .map(this::verse)
+        .collect(Collectors.joining("\n"));
+  }
+
+  @Override
+  public String song() {
+    return verses(99, 0);
+  }
+
   private String capitalize(String text) {
     return text.substring(0, 1).toUpperCase() + text.substring(1);
   }

src/main/java/lars/katas/bottles/ShamelessGreenBottles.java

@@ -3,7 +3,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class ConciseBottles extends Bottles {
+public class Solution_1_IncomprehensiblyConciseBottles implements Bottles {
 
   @Override
   public String verse(int n) {
@@ -29,4 +29,9 @@ public String verses(int start, int end) {
         .map(this::verse)
         .collect(Collectors.joining("\n"));
   }
+
+  @Override
+  public String song() {
+    return verses(99, 0);
+  }
 }

src/main/java/lars/katas/bottles/ConciseBottles.java src/main/java/lars/katas/bottles/Solution_1_IncomprehensiblyConciseBottles.java

@@ -4,7 +4,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class SpeculativelyGeneralBottles extends Bottles {
+public class Solution_2_SpeculativelyGeneralBottles implements Bottles {
 
   private Function<Verse, String> noMore =
       (verse) ->
@@ -50,6 +50,11 @@ public String verses(int start, int end) {
         .collect(Collectors.joining("\n"));
   }
 
+  @Override
+  public String song() {
+    return verses(99, 0);
+  }
+
   private Verse verseFor(int number) {
     switch (number) {
       case 0:

src/main/java/lars/katas/bottles/SpeculativelyGeneralBottles.java src/main/java/lars/katas/bottles/Solution_2_SpeculativelyGeneralBottles.java

@@ -1,12 +1,27 @@
 package lars.katas.bottles;
 
-public class ConcretelyAbstractBottles extends Bottles {
+import java.util.stream.IntStream;
+
+public class Solution_3_ConcretelyAbstractBottles implements Bottles {
 
   @Override
   public String verse(int bottles) {
     return new Round(bottles).toString();
   }
 
+  @Override
+  public String verses(int start, int end) {
+    return IntStream.iterate(start, i -> i >= end, i -> i - 1)
+        .mapToObj(this::verse)
+        .reduce((v1, v2) -> v1 + "\n" + v2)
+        .orElse("");
+  }
+
+  @Override
+  public String song() {
+    return verses(99, 0);
+  }
+
   private class Round {
 
     private int bottles;

src/main/java/lars/katas/bottles/ConcretelyAbstractBottles.java src/main/java/lars/katas/bottles/Solution_3_ConcretelyAbstractBottles.java

@@ -0,0 +1,44 @@
+package lars.katas.bottles;
+
+import java.util.stream.IntStream;
+
+public class Solution_4_ShamelessGreenBottles implements Bottles {
+
+  @Override
+  public String verse(int number) {
+    return switch (number) {
+      case 0 -> "No more bottles of beer on the wall, "
+                + "no more bottles of beer.\n"
+                + "Go to the store and buy some more, "
+                + "99 bottles of beer on the wall.\n";
+      case 1 -> "1 bottle of beer on the wall, "
+                + "1 bottle of beer.\n"
+                + "Take it down and pass it around, "
+                + "no more bottles of beer on the wall.\n";
+      case 2 -> "2 bottles of beer on the wall, "
+                + "2 bottles of beer.\n"
+                + "Take one down and pass it around, "
+                + "1 bottle of beer on the wall.\n";
+      default -> number
+                 + " bottles of beer on the wall, "
+                 + number
+                 + " bottles of beer.\n"
+                 + "Take one down and pass it around, "
+                 + (number - 1)
+                 + " bottles of beer on the wall.\n";
+    };
+  }
+
+  @Override
+  public String verses(int start, int end) {
+    return IntStream.iterate(start, i -> i >= end, i -> i - 1)
+        .mapToObj(this::verse)
+        .reduce((v1, v2) -> v1 + "\n" + v2)
+        .orElse("");
+  }
+
+  @Override
+  public String song() {
+    return verses(99, 0);
+  }
+}

src/main/java/lars/katas/bottles/Solution_4_ShamelessGreenBottles.java

@@ -0,0 +1,41 @@
+package lars.katas.bottles;
+
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class Solution_5_LarsFirstAttemptBottles implements Bottles {
+
+  public String verse(int n) {
+    if (n == 0) {
+      return "No more bottles of beer on the wall, no more bottles of beer.\n"
+          + "Go to the store and buy some more, 99 bottles of beer on the wall.\n";
+    }
+
+    String result = "";
+
+    String bottles = n == 1 ? "bottle" : "bottles";
+    result += String.format("%d %s of beer on the wall, %d %s of beer.\n", n, bottles, n, bottles);
+
+    int afterBottleCount = n - 1;
+    String afterBottles = n - 1 == 1 ? "bottle" : "bottles";
+
+    if (afterBottleCount == 0) {
+      result += "Take it down and pass it around, ";
+      result += "no more bottles of beer on the wall.\n";
+    } else {
+      result += "Take one down and pass it around, ";
+      result += String.format("%d %s of beer on the wall.\n", afterBottleCount, afterBottles);
+    }
+    return result;
+  }
+
+  public String verses(int start, int end) {
+    return Stream.iterate(start, i -> i >= end, i -> i - 1)
+        .map(this::verse)
+        .collect(Collectors.joining("\n"));
+  }
+
+  public String song() {
+    return verses(99, 0);
+  }
+}

src/main/java/lars/katas/bottles/Solution_5_LarsFirstAttemptBottles.java

@@ -10,7 +10,7 @@
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 class BottlesTest {
 
-  private final Bottles bottles = new ShamelessGreenBottles();
+  private final Bottles bottles = new Solution_4_ShamelessGreenBottles();
 
   @Test
   void test_the_first_verse() {

src/test/java/lars/katas/bottles/BottlesTest.java

@@ -11,11 +11,11 @@ class ParameterizedBottlesTest {
 
   private static Stream<Arguments> bottles() {
     return Stream.of(
-        Arguments.of(new Bottles()),
-        Arguments.of(new ConciseBottles()),
-        Arguments.of(new SpeculativelyGeneralBottles()),
-        Arguments.of(new ConcretelyAbstractBottles()),
-        Arguments.of(new ShamelessGreenBottles()));
+        Arguments.of(new Solution_5_LarsFirstAttemptBottles()),
+        Arguments.of(new Solution_1_IncomprehensiblyConciseBottles()),
+        Arguments.of(new Solution_2_SpeculativelyGeneralBottles()),
+        Arguments.of(new Solution_3_ConcretelyAbstractBottles()),
+        Arguments.of(new Solution_4_ShamelessGreenBottles()));
   }
 
   @ParameterizedTest