Good idea: "invert, alway invert" as some old algebraist said. However, this is not the way it should be. That the tests are ok does not necessarily mean that the code is correct. To think so is similar to the argument, that the world is flat just because we can do some steps without returning immediately to the starting point.

But I completely agree with the idea that it would be nice to generate test stubs automatically (or method stubs from tests). Sometimes a piece of code requires a very intensive teste so that one easily forgets to test the rest.

Ok, this might be a sign
of bad design.
Or it means simply that the problem to be solved is not really trivial.