Testing can be key to software quality assurance. Automated verification may increase throughput and reduce human fallibility errors. Test scripts supply inputs, run programs and check their outputs mechanically using test oracles. In software engineering implicit oracles automatically check for universally undesirable behaviour, such as the software under test crashing. We propose 4 properties (probability distributions, fixed qubit width, reversibility and entropy conservation) which all quantum computing must have and suggest they could be implicit test oracles for automatic, random, or fuzz testing of quantum circuits and simulators of quantum programs.