多次模拟时Mockito UnfinishedStubbingException

Question

我想在我的 Invoice 类中存根方法 generateReferenceNumber()：

public class Invoice {

    private String id;
    private String referenceNumber;
    private Date issueDate;
    private PaymentMethod paymentMethod;
    private Date paymentDate;
    private String shopId;
    private List<InvoiceGroupItem> groupItems;
    private InvoiceStatus status;

    public void moveToNextState() {
        status = status.nextState();
    }

    public void generateReferenceNumber() {
        if (referenceNumber != null) {
            return;
        }

        referenceNumber = new InvoiceReference().createNew(issueDate).toString();
    }
}

此对象用于我要测试的服务。为此，我需要多张发票。所以我写了以下代码：

private Stream<Invoice> buildApprovedInvoice() {
    val approvedInvoices = new ArrayList<Invoice>();

    for (int i = 0; i < 10; i++) {
        val invoice = Invoice.builder().build();
        val spy = spy(invoice);

        doAnswer(invocation -> {
            final Invoice mock = (Invoice) invocation.getMock();
            mock.setReferenceNumber("Invoice reference number");
            return null;
        }).when(spy).generateReferenceNumber();

        approvedInvoices.add(spy);
    }

    return approvedInvoices.stream();
}

当我执行测试时，出现以下错误：

org.mockito.exceptions.misusing.UnfinishedStubbingException： 此处检测到未完成的存根： -> 在 com.coruscant.core.services.invoice.InvoiceSendingServiceTest.sendInvoices(InvoiceSendingServiceTest.java:54)

例如thenReturn() 可能会丢失。正确的存根示例： 当（模拟。isOk（））。然后返回（真）； when(mock.isOk()).thenThrow(异常); doThrow(exception).when(mock).someVoidMethod();

有人知道为什么吗？

谢谢。

Answer 1

您不需要模拟 Invoice 来测试它。或者，如果是单元测试，您可以模拟 InvoiceReference。如果是集成测试：

class Test {

   private Invoice invoice;

   @BeforeEach
   void setUp() {
      invoice - new Invoice();
   }
   @Test
   void shouldSetReferenceNumber_WhenReferenceNumberEqualsNull() {
      invoice.setIssueDate(new Date());
      invoice.generateReferenceNumber();
      assertThat(invoice).hasFieldWithValue("referenceNumber", expectingValue);
   }

   @Test
   void shouldNotSetReferenceNumber_WhenReferenceNumberIsNotEqualsNull() {
      invoice.setReferenceNumber("test-reference-number");
      invoice.generateReferenceNumber();
      assertThat(invoice).hasFieldWithValue("referenceNumber", "test-reference-number");
   }
}

单元测试（模拟 InvoiceReference）：

public class Invoice {

    private String id;
    private String referenceNumber;
    private Date issueDate;
    private PaymentMethod paymentMethod;
    private Date paymentDate;
    private String shopId;
    private List<InvoiceGroupItem> groupItems;
    private InvoiceStatus status;

    public void moveToNextState() {
        status = status.nextState();
    }

    public void generateReferenceNumber() {
        if (referenceNumber != null) {
            return;
        }

        getInvoiceReference().createNew(issueDate).toString(); 
    }

   public InvoiceReference getInvoiceReference() {
      return new InvoiceReference();
   }
}

class Test {

   private Invoice invoice;
   @Mock
   private InvoiceReference invoiceReference;

   @BeforeEach
   void setUp() {
      invoice = new Invoice();
      MockitoAnnotations.initMocks(this);
      when(invoiceReference.createNew(any(Date.class)).thenReturn("test-reference-number");
   }

   @Test
   void shouldSetReferenceNumber_WhenReferenceNumberEqualsNull() {
      invoice.setIssueDate(new Date());
      invoice.generateReferenceNumber();
      assertThat(invoice).hasFieldWithValue("referenceNumber", "test-reference-number");
   }

   @Test
   void shouldNotSetReferenceNumber_WhenReferenceNumberIsNotEqualsNull() {
      invoice.setReferenceNumber("different_reference_number");
      invoice.generateReferenceNumber();
      assertThat(invoice).hasFieldWithValue("referenceNumber", "different_reference_number");
   }
}