turn left successfully

src/main/java/cat/hack3/codingtests/marsrover/MarsMap.java

@@ -1,6 +1,9 @@
 package cat.hack3.codingtests.marsrover;
 
+import static cat.hack3.codingtests.marsrover.MarsMap.Direction.*;
+
 public class MarsMap {
+    public enum Direction {NORTH, SOUTH, EAST, WEST}
     private final int width;
     private final int height;
 
@@ -9,5 +12,12 @@ public class MarsMap {
         this.height = height;
     }
 
-    public enum Direction {NORTH, SOUTH, EAST, WEST}
+    public Direction changeDirectionToLeft(Direction currentDirection) {
+        return switch (currentDirection) {
+            case NORTH -> WEST;
+            case SOUTH -> EAST;
+            case EAST -> NORTH;
+            case WEST -> SOUTH;
+        };
+    }
 }

src/main/java/cat/hack3/codingtests/marsrover/MarsRover.java

@@ -20,7 +20,16 @@ public class MarsRover {
         };
     }
 
+    public MarsMap.Direction turnLeft() {
+        currentDirection = marsMap.changeDirectionToLeft(currentDirection);
+        return currentDirection;
+    }
+
     public Coordinates getCurrentCoordinates() {
         return currentCoordinates;
     }
+
+    public MarsMap.Direction getCurrentDirection() {
+        return currentDirection;
+    }
 }

src/test/java/cat/hack3/codingtests/marsrover/MarsRoverTest.java

@@ -3,9 +3,11 @@ package cat.hack3.codingtests.marsrover;
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.Test;
 
+import java.util.function.IntConsumer;
 import java.util.stream.IntStream;
 
-import static cat.hack3.codingtests.marsrover.MarsMap.Direction.SOUTH;
+import static cat.hack3.codingtests.marsrover.MarsMap.Direction;
+import static cat.hack3.codingtests.marsrover.MarsMap.Direction.*;
 import static org.testng.Assert.assertEquals;
 
 public class MarsRoverTest {
@@ -29,12 +31,28 @@ public class MarsRoverTest {
     public void roverMakeItsFirstStep() {
         Coordinates currentPosition = rover.moveForward();
         assertEquals(currentPosition, Coordinates.of(3, 3));
+        assertEquals(rover.getCurrentDirection(), SOUTH);
     }
 
     @Test
     public void make5StepsInARow() {
-        IntStream.rangeClosed(0, 5)
-                .forEach(i -> rover.moveForward());
+        repeatAction(5, i -> rover.moveForward());
         assertEquals(rover.getCurrentCoordinates(), Coordinates.of(8, 3));
+        assertEquals(rover.getCurrentDirection(), SOUTH);
+    }
+
+    @Test
+    public void turnLef() {
+        Direction currentDirection = rover.turnLeft();
+        assertEquals(currentDirection, EAST);
+        assertEquals(rover.turnLeft(), NORTH);
+        assertEquals(rover.turnLeft(), WEST);
+        repeatAction(2, i -> rover.turnLeft());
+        assertEquals(currentDirection, EAST);
+    }
+
+    private void repeatAction(int times, IntConsumer actionToRepeat) {
+        IntStream.rangeClosed(0, times)
+                .forEach(actionToRepeat);
     }
 }