CODEWITHSUNDEEP
javaunit-testingjunitmockito
Squeez
Squeez

Reputation: 959

How can I check method params when method call using mockito?

I am trying to write unit test which will test fillA method. I need to verify that doSmth calling with correctly initialized a fields. Here is example.

SecondClass secondClass = new SecondClass();

public void execute() {
  A a = new A();
  fillA(a);
  secondClass.doSmth(a);
}

private void fillA(A a) {
  a.setFirstField("first field");
  a.setSecondField("second field");
}

class SecondClass {
  public void doSmth(A a) {
    // doSmth
  }
}

class A {
  private String firstField;
  private String secondField;

  // getters and setters
}

Upvotes: 0

Views: 143

Answers (2)

gontard
gontard

Reputation: 29520

To ensure, that secondClass is invoked, you should use Mockito.verify.

verify(): to check methods were called with given arguments can use flexible argument matching, for example any expression via the any() or capture what arguments where called using @Captor instead.

For example:

Mockito.verify(secondClass).doSmth(<arg>);

If you want to check that the a fields are correctly initialized, <arg> could be:

  • an instance of A (new A("first field", "second field")), if A define a proper equals

    Arguments passed are compared using equals() method"

  • a custom A ArgumentMatcher

  • an ArgumentCaptor

Upvotes: 2

Duncan Jones
Duncan Jones

Reputation: 69339

Here's the basic structure of the test you need. You need to mock your SecondClass instance and inject this into your class under test. I've named your outer class as Bar.

This code assumes you implement a .equals() method on the A class.

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.runners.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class BarTest {

  @Test
  public void testAIsCorrectlyInitialized() throws Exception {
    SecondClass secondClass = mock(SecondClass.class);
    Bar bar = new Bar();
    bar.setSecondClass(secondClass);

    A expected = new A();
    // here, populate "expected" with correct values

    bar.execute();

    // Verify call (assumes A implements a proper equals)
    verify(secondClass).doSmth(expected);
  }
}

Upvotes: 0

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