src/main/java/Action/DigAction.java

@@ -16,8 +16,7 @@ public class DigAction implements Action {
     }
 
     private Miner requireMiner(Actor actor) {
-        if (actor instanceof JobHolder hasJob
+        if (actor.getJob() instanceof Miner miner) {
-                && hasJob.getJob() instanceof Miner miner) {
             return miner;
         }
         throw new IllegalStateException(actor + " cannot perform this action without being a Miner!");

src/test/java/DigActionTest.java

@@ -27,4 +27,12 @@ public class DigActionTest {
         var action =  new DigAction(biome);
         assertThrows(IllegalStateException.class, () -> action.execute(player));
     }
+
+    @Test
+    void digging_when_not_have_job_throws_error() {
+        var player = mock(Player.class);
+        var biome = mock(Biome.class);
+        var action =  new DigAction(biome);
+        assertThrows(IllegalStateException.class, () -> action.execute(player));
+    }
 }