Add BotTest for movement bounds and preference (#42)

Author: hippi345

src/test/java/sample/models/BotTest.java

@@ -0,0 +1,36 @@
+package sample.models;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class BotTest {
+
+    @Test
+    void singleCellGridStaysPut() {
+        Bot bot = new Bot(1);
+        assertEquals(MoveEnum.Stay, bot.determineMovement());
+    }
+
+    @Test
+    void determinedMovesNeverLeaveTheGrid() {
+        Bot bot = new Bot(3);
+        for (int i = 0; i < 500; i++) {
+            bot.move(bot.determineMovement());
+            assertTrue(bot.getX() >= 0 && bot.getX() < 3);
+            assertTrue(bot.getY() >= 0 && bot.getY() < 3);
+        }
+    }
+
+    @Test
+    void prefersTheOnlyUnvisitedNeighbor() {
+        Bot bot = new Bot(2);
+        bot.relocate(0, 0);
+        bot.move(MoveEnum.Right);
+        bot.move(MoveEnum.Left);
+        for (int i = 0; i < 50; i++) {
+            assertEquals(MoveEnum.Down, bot.determineMovement());
+        }
+    }
+}