Bug #20442: Printing class variable inconsistent when using nested hashes

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: 3.3.0
• Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[k776 (Kieran Pilkington)]

See attached test.rb. I have a class with a class variable. The idea is simple, increment the value and then print out the resulting class var.

Mock1
0
1

Mock2
{}
{"a"=>1}

Mock3
{}
{"a"=>1}

Mock4
{}
{}

Mock1 through Mock3 are working as expected. But Mock4 does not, it outputs a blank hash, rather than the expected: {"a"=>{"a"=>1}}

The value is being set. If I replace the print method with @val['a']['a'] is outputs the number 1 as expected.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Rejected

Not a bug. For the behavior you want, in Mock4

  @val = Hash.new{|h, k| h[k] = Hash.new(0)}

With @val = Hash.new(Hash.new(0)), the @val['a'] expression returns the Hash.new(0) default value, but does not set a value in @val.