Mutation testing is an active research area.

Mutation Testing for Energy-Awareness

• Testing for defects in the energy-behaviour of mobile apps can be assessed using mutation operators specifically designed for the purpose.
• Reyhaneh Jabbarvand, Sam Malek, µDroid: an energy-aware mutation testing framework for Android, ESEC/FSE 2017

Focused Mutation Testing on Change Sets (Deltas)

• When changes to source code are made, the cost of mutation testing can be reduced and the effectiveness increased by focusing on the change program statements only.
• W. Ma, T. Titcheu Chekam, M. Papadakis and M. Harman, "MuDelta: Delta-Oriented Mutation Testing at Commit Time," ICSE 2021