Mockito UnfinishedStubbingException when mocking multiple times

Question

I want to stub the methot generateReferenceNumber() in my Invoice class :

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();
    }
}

This object is used in a service which I want to test. For that purpose I need multiple Invoices. So I wrote de following code :

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();
}

And when I execute the test, I get the following error :

org.mockito.exceptions.misusing.UnfinishedStubbingException: Unfinished stubbing detected here: -> at com.coruscant.core.services.invoice.InvoiceSendingServiceTest.sendInvoices(InvoiceSendingServiceTest.java:54)

E.g. thenReturn() may be missing. Examples of correct stubbing: when(mock.isOk()).thenReturn(true); when(mock.isOk()).thenThrow(exception); doThrow(exception).when(mock).someVoidMethod();

Anyone has an idea why ?

Thank you.

I am pretty sure the exception is not coming from the code that is displayed in your question. Can you provide a minimal reproducible example that produces the exception? — second

Misha Lemko Misha Lemko · Accepted Answer · 2020-02-28T12:54:58

You don't need to mock Invoice for testing it. Or you can mock InvoiceReference if it is unit test. If it is integration test:

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");
   }
}

Unit test(mock 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");
   }
}

Mockito UnfinishedStubbingException when mocking multiple times

1 Answers