Bug #21152: Enumerator's #size returned by Range#reverse_each raises an exception for endless Range

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: 3.4.2
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[andrykonchin (Andrew Konchin)]

I've noticed a change between 3.3 and 3.4 in a way how Range#reverse_each behaves:

Ruby 3.3:

Range.new("a", nil).size # => nil
Range.new(1, nil).size # => Infinity

Range.new("a", nil).reverse_each.size # => nil
Range.new(1, nil).reverse_each.size # => Infinity

Ruby 3.4

Range.new("a", nil).size # => nil
Range.new(1, nil).size # => Infinity

Range.new("a", nil).reverse_each.size # can't iterate from NilClass (TypeError)
Range.new(1, nil).reverse_each.size # can't iterate from NilClass (TypeError)