org.assertj.core.api

Interface AssertDelegateTarget

public interface AssertDelegateTarget

A marker interface that can be used to wrap your assertion within assertThat method for better readability.

Consider the following MyButton and MyButtonAssert classes:

 public class MyButton extends JButton {

   private boolean blinking;

   public boolean isBlinking() { return this.blinking; }

   public void setBlinking(boolean blink) { this.blinking = blink; }

 }

 private static class MyButtonAssert implements AssertDelegateTarget {

   private MyButton button;
   MyButtonAssert(MyButton button) { this.button = button; }

   void isBlinking() {
     // standard assertion from core Assertions.assertThat
     assertThat(button.isBlinking()).isTrue();
   }

   void isNotBlinking() {
     // standard assertion from core Assertions.assertThat
     assertThat(button.isBlinking()).isFalse();
   }
 }

As MyButtonAssert implements AssertDelegateTarget, you can use assertThat(buttonAssert).isBlinking(); instead of buttonAssert.isBlinking(); to have easier to read assertions.

 @Test
 public void AssertDelegateTarget_example() {

   MyButton button = new MyButton();
   MyButtonAssert buttonAssert = new MyButtonAssert(button);

   // you can encapsulate MyButtonAssert assertions methods within assertThat
   assertThat(buttonAssert).isNotBlinking(); // same as : buttonAssert.isNotBlinking();

   button.setBlinking(true);

   assertThat(buttonAssert).isBlinking(); // same as : buttonAssert.isBlinking();
 }

Author:

Christian Rösch