CAT 020

CAT-020 — IO::Memory for unread output

Field	Value
Severity	warning
Confidence	high
Auto-fix	✅

IO::Memory for unread output — Creating an IO::Memory just to build a string that's immediately passed to a sink is wasteful. Use String.build instead.

Bad code

io = IO::Memory.new
io << "hello"
io.to_s

Good code

String.build { |io| io << "hello" }