%a{pure} does not seem to work for attr_reader about rbs HOT 3 CLOSED

Did you mean? Steep still consider b to be String?, not String

I’ve reproduced in Steep 1.7 but it is able to type-narrow using the if statement with or without %a{pure}.
OTOH, Steep does not type narrow without the if statement by inferring from #initialize

I get Cannot find implementation of method `::A#b` somehow, but it does not impact the topic.

from rbs.

Aren’t attr_XXX be pure by definition?
unless they’re used by lazy people to write RBS for their custom accessors

from rbs.

you're correct, it's already pure. I got confused by the message.

from rbs.