Currently, Style/NegatedIf (and Style/NegatedUnless) recommend if x over unless !x, which is good because negations are less natural for the reader.

What might be useful is a cop that goes a step further and recommends if x || y over unless !x && !y. That is, a cop that reduces the number of negations in a boolean expression as much as possible by leveraging DeMorgan's Rule.

In its basic form, it could look for conjunctions (or disjunctions) where all terms are negated:

# bad (all terms negated)
unless !x && !y && !z

# good (all terms positive)
if x || y || z

A more complex version could look for conjunctions (or disjunctions) where there are more negations than positives:

# bad (3 negations, 1 positive)
unless !x || !y || !z || w

# good (3 positives, 1 negation)
if x && y && z && !w

Does this sound reasonable? 🤔