src/main/java/Monster/Nixie.java

@@ -1,8 +0,0 @@
-package Monster;
-
-public abstract class Nixie extends Monster implements CanMove, CanAttack {
-
-    public Nixie() {
-        super(0,0,Monster.DEFAULT_POSITION);
-    }
-}

src/main/java/Monster/Troll.java

@@ -101,7 +101,7 @@ public class Troll extends Monster implements CanMove, CanAttack {
         if (playerIsAtPosition(destination, world)) {
             return false;
         }
-        if (tileHasWrongHabitat(position, world)) {
+        if (tileHasWrongHabitat(destination, world)) {
             return false;
         }
 

src/test/java/MonsterTest.java

@@ -205,4 +205,16 @@ public class MonsterTest {
         assertThat(defaultTroll.moveTo(destination, world), equalTo(false));
     }
 
+    @Test
+    void troll_can_move_to_tile_within_its_habitat() {
+        when(mockTile.getBiome()).thenReturn(Biomes.FOREST);
+        Position destination = new Position(1, 3);
+
+        worldGenerator.randomWorldGeneration();
+        World world = worldGenerator.getWorld();
+        world.addTile(mockTile, destination);
+
+        assertThat(defaultTroll.moveTo(destination, world), equalTo(true));
+    }
+
 }