PubSubTest.java

import org.junit.Test;

import java.lang.ref.WeakReference;

import static org.junit.Assert.*;

public class PubSubTest {


    @Test
    public void notWtf() {
        WeakReference<Runnable> reference = new WeakReference<Runnable>(new Runnable() {
            @Override
            public void run() {
                // ...
            }
        });

        forceGc();
        assertNull(reference.get());
    }

    @Test
    public void lambdaWtf() {
        WeakReference<Runnable> reference = new WeakReference<Runnable>(() -> Integer.valueOf(1) );

        forceGc();
        assertNull(reference.get());
    }

    
    public void forceGc() {
        try {
            Object[] ignored = new Object[(int) Runtime.getRuntime().maxMemory()];
        } catch (Throwable e) {
            // Ignore OME
        }

        System.gc();
    }
    
}