Question

I’m trying to write a unit test that needs to confirm if a method is called or not. I’m using JUnit, Mockito and PowerMock.

public class Invoice
{

  protected void createInvoice()
  {
    // random stuff here
    markInvoiceAsBilled("57");
  }

  protected void markInvoiceAsBilled(String code)
  {
    // marked as billed
  } 
}

So, here my system under test is Invoice. I’m running this test:

  public class InvoiceTest
  {
    @Test
    public void testInvoiceMarkedAsBilled()
    {
      Invoice sut = new Invoice();
      Invoice sutSpy = spy(sut);

      sut.createInvoice();

      // I want to verify that markInvoiceAsBilled() was called
    }
  }

This example is just an example of what the actual code looks like….

My problem is that mockito says you can only verify if a method is called on a mocked object… but I don’t want to mock this object, as it’s my object under test. I know that you can spy on the object you’re testing, so here’s what I tried:

  verify(sutSpy).markInvoiceAsBilled("57");

Is what I’m trying to do not possible? Or am I just going about it the wrong way?

Thanks everyone 🙂

Answer 1

I’m not sure if what you are attempting to do is the best way to go about things.

I wouldn’t concern myself with verifying that Invoice.createInvoice() calls an internal, private method markInvoiceAsBilled() – instead test that calling createInvoice() changes the state of the Invoice object in the way you expect – i.e., that status is now BILLED or something similar.

In other words – don’t test what methods are called by createInvoice() – test that after calling this method, the state of the object is what you expect.