Use assertEquals(expected, actual, delta) to compare floating-point numbers. This call to assertEquals() will either fail or not compile in JUnit 4. Use assertEquals(expected, actual, 0.0) if the delta must be 0.0.

Alternatively, one can use Google Truth library's DoubleSubject class which has both isEqualTo() for delta 0.0 and isWithin() for non-zero deltas.