Google is working on noop as a language (OOP, Java-based) created to produce code that is always testable.
Noop is a new language that will run on the Java Virtual Machine, and in source form will look similar to Java. The goal is to build dependency injection and testability into the language from the beginning, rather than rely on third-party libraries as other languages do.
The language also explicitly forbids certain constructs that make it harder to test code, like for instance statics.