Testing 404 in @WebMvcTest

@WebMvcTest(OrderController.class)
class OrderControllerTest {
    @Autowired
    private MockMvc mockMvc;
    
    @MockBean
    private OrderService orderService;
    
    @Test
    void shouldReturn404WhenOrderNotFound() throws Exception {
        var orderId = 999L;
        // Stub service to throw exception
        when(orderService.findById(orderId))
            .thenThrow(new ResourceNotFoundException("Order not found"));
        
        mockMvc.perform(get("/api/orders/{id}", orderId))
            .andExpect(status().isNotFound())
            .andExpect(jsonPath("$.message").value("Order not found"));
    }
}

@ControllerAdvice
class GlobalExceptionHandler {
    @ExceptionHandler(ResourceNotFoundException.class)
    @ResponseStatus(HttpStatus.NOT_FOUND)  // Maps to 404
    public ErrorResponse handleNotFound(ResourceNotFoundException ex) {
        return new ErrorResponse(ex.getMessage());
    }
}

record ErrorResponse(String message) {}