CAT 006

CAT-006 — hash.keys.each → each_key

Field	Value
Severity	info
Confidence	high
Auto-fix	✅

hash.keys.each → each_key — Use each_key instead of .keys.each to avoid allocating an intermediate array of keys.

Bad code

hash.keys.each { |k| ... }

Good code

hash.each_key { |k| ... }