rover: add rover starting on obstacle validation

rover/rover.py

@@ -93,6 +93,13 @@ class Commander(BaseModel):
     rover: Rover = Rover()
     obstacles: List[Vector] = []
 
+    @root_validator()
+    def _rover_should_not_start_on_obstacle(cls, values):
+        rover, obstacles = values.get("rover"), values.get("obstacles")
+        if rover.pos in obstacles:
+            raise ValueError(f"Rover should not start on obstacle ({rover.pos})")
+        return values
+
     def parse_execute(self, commands: str):
         for command in commands:
             save: Vector = deepcopy(self.rover.pos)

rover/test_rover.py

@@ -247,3 +247,8 @@ def test_rover_oversize_x_construction():
 def test_rover_oversize_y_construction():
     with pytest.raises(ValidationError):
         _ = Rover(pos=Vector(x=0, y=11), planet_size=Vector(x=10, y=10))
+
+
+def test_commander_have_rover_start_on_obstacle():
+    with pytest.raises(ValidationError):
+        _ = Commander(obstacles=[Vector()])