F!! Storyboard to verify sequences

Author: actions-user

approvaltests-tests/src/test/java/org/approvaltests/StoryBoardTest.gameOfLife.approved.txt

@@ -0,0 +1,30 @@
+Initial:
+.  .  .  .  .  
+.  .  .  .  .  
+.  x  x  x  .  
+.  .  .  .  .  
+.  .  .  .  .  
+
+
+Frame #1:
+.  .  .  .  .  
+.  .  x  .  .  
+.  .  x  .  .  
+.  .  x  .  .  
+.  .  .  .  .  
+
+
+Frame #2:
+.  .  .  .  .  
+.  .  .  .  .  
+.  x  x  x  .  
+.  .  .  .  .  
+.  .  .  .  .  
+
+
+Frame #3:
+.  .  .  .  .  
+.  .  x  .  .  
+.  .  x  .  .  
+.  .  x  .  .  
+.  .  .  .  .  

approvaltests-tests/src/test/java/org/approvaltests/StoryBoardTest.java

@@ -0,0 +1,52 @@
+package org.approvaltests;
+
+import org.junit.jupiter.api.Test;
+import org.lambda.functions.Function2;
+import org.lambda.query.Queryable;
+import org.lambda.utils.Grid;
+
+public class StoryBoardTest
+{
+  @Test
+  void gameOfLife()
+  {
+    final GameOfLife gameOfLife = new GameOfLife((x, y) -> y == 2 && 1 <= x && x <= 3);
+    final Storyboard storyboard = new Storyboard();
+    storyboard.add(gameOfLife);
+    storyboard.addFrames(3, gameOfLife::advance);
+    Approvals.verify(storyboard);
+  }
+  private class GameOfLife
+  {
+    private Function2<Integer, Integer, Boolean> board;
+    public GameOfLife(Function2<Integer, Integer, Boolean> board)
+    {
+      this.board = board;
+    }
+    public GameOfLife advance()
+    {
+      final Function2<Integer, Integer, Boolean> old = this.board;
+      this.board = (x, y) -> {
+        final int aliveNeighbours = Queryable.as(
+            old.call(x - 1, y - 1),
+            old.call(x - 0, y - 1),
+            old.call(x + 1, y - 1),
+            old.call(x - 1, y - 0),
+//            old.call(x - 0, y - 0),
+            old.call(x + 1, y - 0),
+            old.call(x - 1, y + 1),
+            old.call(x - 0, y + 1),
+            old.call(x + 1, y + 1)
+        ).where(a -> a)
+            .size();
+        return aliveNeighbours == 3 || (aliveNeighbours == 2 && old.call(x, y));
+      };
+      return this;
+    }
+    @Override
+    public String toString()
+    {
+      return Grid.print(5, 5, (x, y) -> board.call(x, y) ? "x " : ". ");
+    }
+  }
+}

approvaltests/src/main/java/org/approvaltests/Storyboard.java

@@ -0,0 +1,26 @@
+package org.approvaltests;
+
+import org.lambda.functions.Function0;
+
+public class Storyboard
+{
+  private StringBuffer stringBuffer = new StringBuffer();
+  int                  index        = 0;
+  public void add(Object object)
+  {
+    String title = index == 0 ? "Initial:" : "\n\nFrame #" + index + ":";
+    stringBuffer.append(String.format("%s\n%s", title, object));
+    index++;
+  }
+  public void addFrames(int howMany, Function0<Object> getNextFrame)
+  {
+    for (int i = 0; i < howMany; i++) {
+      add(getNextFrame.call());
+    }
+  }
+
+  @Override
+  public String toString() {
+    return stringBuffer.toString();
+  }
+}