@Deprecated
public static void assertEquals(double expected, double actual)

private static final double DELTA = 1e-15;

@Test
public void testDelta(){
    assertEquals(123.456, 123.456, DELTA);
}

private static final double DELTA = 1e-15;

@Test
public void testDelta(){
    assertThat(123.456, equalTo(123.456);
    assertThat(123.456, closeTo(123.456, DELTA));
}

Assert.assertEquals(Double.doubleToLongBits(expected), Double.doubleToLongBits(result));

Assert.assertEquals(0, Double.compareTo(expected, result));

public interface Foo {
    double getDefaultValue();
}

public class FooImpl implements Foo {
    public double getDefaultValue() { return Double.MIN_VALUE; }
}

double defaultValue = new FooImpl().getDefaultValue();
assertEquals(Double.MIN_VALUE, defaultValue);

// really you just need one cast because of autoboxing, but let's be clear
assertEquals((Object)Double.MIN_VALUE, (Object)defaultValue);

assertEquals(
    Double.doubleToLongBits(Double.MIN_VALUE),
    Double.doubleToLongBits(defaultValue)
);

// equivalent to assertEquals((Object)Double.MIN_VALUE, (Object)defaultValue);
assertThat(defaultValue, is(Double.MIN_VALUE));