Rule proposal: Test function bodies should always be blocks

[raphinesse]

Would there be interest in a rule that enforces that test function bodies always be blocks?

// BAD: Test function bodies should always be blocks (at 1:38)
it('should always use blocks', () => testSubject().then(
// ----------------------------------^
  result => expect(result).toBe(42)
));

// OK
it('should always use blocks', () => {
  return testSubject()
    .then(result => expect(result).toBe(42));
});

Implementation prototype with samples

[DianaSuvorova]

Yes! New rules are welcome!

I wouldn't include this one as an error for default configuration, but definitely would be a good contribution so people can decide if they want this as a convention for their projects.