package beginner;

import com.sandwich.koan.Koan;

import static com.sandwich.koan.constant.KoanConstants.__;

import static com.sandwich.util.Assert.*;

public class AboutEquality {

@Koan

public void doubleEqualsTestsIfTwoObjectsAreTheSame(){

Object object = new Object();

Object sameObject = object;

assertEquals(object == sameObject, __);

assertEquals(object == new Object(), __);

}

@Koan

public void equalsMethodByDefaultTestsIfTwoObjectsAreTheSame(){

Object object = new Object();

assertEquals(object.equals(object), __);

assertEquals(object.equals(new Object()), __);

}

@Koan

public void equalsMethodCanBeChangedBySubclassesToTestsIfTwoObjectsAreEqual(){

Object object = new Integer(1);

assertEquals(object.equals(object), __);

assertEquals(object.equals(new Integer(1)), __);

// Note: This means that for the class 'Object' there is no difference between 'equal' and 'same'

}

@Koan

public void objectsNeverEqualNull(){

assertEquals(new Object().equals(null), __);

}

@Koan

public void objectsEqualThemselves(){

Object obj = new Object();

assertEquals(obj.equals(obj), __);

}

}