How do you test code that uses IdentityHashMap?

Testing code that uses IdentityHashMap in Java can be accomplished using various testing frameworks like JUnit or Mockito. Since IdentityHashMap uses reference equality for its keys, it's essential to understand how this functionality can impact your tests, especially when comparing key values.

Example of Testing IdentityHashMap


import java.util.IdentityHashMap;
import org.junit.Assert;
import org.junit.Test;

public class IdentityHashMapTest {
    @Test
    public void testIdentityHashMap() {
        IdentityHashMap map = new IdentityHashMap<>();
        
        String key1 = new String("key");
        String key2 = new String("key"); // different object reference
        
        map.put(key1, "value1");
        map.put(key2, "value2");
        
        // should return "value1" because key1 and key2 are different objects
        Assert.assertEquals("value1", map.get(key1));
        Assert.assertEquals("value2", map.get(key2));
    }
}

IdentityHashMap Java Testing JUnit Key Reference Equality Unit Testing

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