How to test presenter method that create a new object inside it?

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I have this method to validate Unit. I send field values and inside it method I create a new model and then return that model via interface.

public void validate(String unitNumber, Integer unitTypeId, String notes) {
if(!TextUtils.isEmpty(unitNumber)) {
      Unit unit = new Unit();
      unit.setUnitNumber(unitNumber);
      unit.setFlatTypeId(unitTypeId);
      unit.setNotes(notes);
      view.displayUnitValid(unit);
    } else {
      view.displayUnitNotValid();
    }
  }

Now I want do do unit testing of this method with the following code.

@Test public void shouldValidateSinceUnitNumberIsValid() {
    // Given
    String unitNumber = "1";

    // When
    presenter.validate(unitNumber, null, null);

    // Then
    Mockito.verify(view).displayUnitValid(new Unit());
 }

I am getting the following error message:

Argument(s) are different! Wanted:
view.displayUnitValid(
    com.rwar.domain.customers.Unit@57cf54e1
);
-> at com.rwar.presentation.work_orders.AddUnitPresenterTest.shouldValidateSinceUnitNumberIsValid(AddUnitPresenterTest.java:73)

Obvisouly there is a problem since I am creating a new Unit instance here:

Mockito.verify(view).displayUnitValid(new Unit());

And inside validate() method I create another instance of Unit.

How I can fix this?

Pass the same arguments to your verifying method, e.g.

Unit expected = new Unit()
unit.setUnitNumber(unitNumber);
unit.setFlatTypeId(unitTypeId);
unit.setNotes(notes);
Mockito.verify(view).displayUnitValid(expected);

You'll likely have to override your Unit classes equals/hashcode method such that they compare their contents and not the instance itself.

Testing and Dependency Injection With Model View Presenter on , To create mock objects, we will use Mockito, which allows us to verify if certain if certain methods were called in Presenter which is responsible for creating a new note and register it in the database using an AsyncTask . Create a test object. You can create a test object in two ways: From the main menu, select File > New > Test Object; Or; Right-click on Object Repository > select New > Test Object; In the displayed New Test Object dialog, provide a name for the new test object, then click OK button. The new test object is created under the Object Repository of

Here is the working solution that might be useful to someone else:

 @Test public void shouldValidateSinceUnitNumberIsValid() {
    // Given
    String unitNumber = "1";

    // When
    presenter.validate(unitNumber, null, null);

    // Then use ArgumentCaptor to get unit value from newly created object inside validate() method
    ArgumentCaptor<Unit> argument = ArgumentCaptor.forClass(Unit.class);
    Mockito.verify(view).displayUnitValid(argument.capture());
    // Compare captured argument of Unit number with local unitNumber
    assertEquals(argument.getValue().getUnitNumber(), unitNumber);
  }

Kotlin: Introduction to testing Android presenters, In this article we will test the presenters in our Android application by using Kotlin, unit tests and mock objects. Also, having proper unit tests can prevent us from breaking already working code when implementing new features or fixing We will use setUp method to construct our CUT (ProfilePresenter)  On the File menu, select Add > New Project. Tip. You can also right-click on the solution in Solution Explorer and choose Add > New Project. In the New Project dialog box, expand Installed, expand Visual C#, and then choose Test. From the list of templates, select MSTest Test Project (.NET Core).

In case you want to do this in Kotlin, you can use Mockito check function to make asserts over the Unit instance that is passed as an argument of displayUnitValid(). Something like this:

Mockito.verify(view).displayUnitValid(Mockito.check { unit ->
    assertEquals(unitNumber, unit.getUnitNumber)
});

More info about check here

How to make MVP testable - Gil Goldzweig Goldbaum, Whenever I create a project, I base it on the MVP design pattern. When the need arises and I'm clicking File -> New Project… I will use Mockito and Junit4 in order to test our presenter. us with a mocked version which is a simulated object that mimics the behavior of the real object in a controlled way. I want to be able to create a new instance of an object by calling a method on an already instantiated object. For example, I have the object: organism = Organism() I want to be able to call organism.reproduce() and have two objects of type Organism. My method at this point looks like this:

How to Unit Test Classes Which Create New Objects, A simple method to write test cases for classes that use new keywords in their method with the help of Mockito and minimum code changes. There is one newInstance() method in the java.lang.reflect.Constructor class which we can use to create objects. It can also call parameterized constructor, and private constructor by using this newInstance() method.

Rails 4 Test Prescriptions: Build a Healthy Codebase, Build a Healthy Codebase Noel Rappin. though it were an instance of the original object, plus the presenter includes any new methods we choose to add to the  When you create a host container object for visual objects, you need to store the visual object references in a VisualCollection. Use the Add method to add a visual object to the host container. In the following example, a host container object is created, and three visual objects are added to its VisualCollection .

How to mock Presenter method in Robolectric ? · Issue #79 , I am new in mockito and robolectric, and just exploring the features. The following test case how we can write using robolectric. public to host and review code, manage projects, and build software together. @Override public Object answer​(InvocationOnMock invocation) throws Throwable { activity. This is the easiest way to create a JavaScript Object. Using an object literal, you both define and create an object in one statement. An object literal is a list of name:value pairs (like age:50) inside curly braces {}. The following example creates a new JavaScript object with four properties:

Comments
  • Seems like your Unit objects are not equal. Try to set a unit number for your unit object in your test case.
  • Yes, I could do that, but then I need to change parameters of validate method to accept Unit model.
  • Is there a way to make it work with my current approach?
  • @Zookey: Why do you think you neet to change parameters? It should work like that (if equals and hashcode are properly implemented). You also have the option to define a custom ArgumentMatcher.
  • Nice ide, but I am using PowerMockito and I do not see this function. (
  • @JaviHerAr: The OP seems to use Java not Kotlin. The check functionality seems to only exist in the mockito-kotlin dependency.
  • @second you are right, I have updated my answer to clarify it