Bug #18582
Updated by nobu (Nobuyoshi Nakada) over 2 years ago
With Ruby 3.0.3, when using SortedSets as group_by value for Hash, equal SortedSets are not grouped as they should be. This works correctly in Ruby 2.7.1 (when rbtree gem is not present, not tested with rbtree gem) This works correctly using Sets as the group_by value in both 2.7.1 and 3.0.3 This test code: ```ruby ``` require 'set' require 'sorted_set' if RUBY_VERSION > '3' puts RUBY_VERSION # works when keys are Sets s1 = Set['fubar'] s2 = Set['fubar'] warn "expected #{s1} to equal #{s2}" unless s1 == s2 grouped = { 'a' => s1, 'b' => s2 }.group_by { |_, v| v } puts "grouped by Sets: #{grouped}" warn "expected 1 key in hash grouped by Sets, got #{grouped.keys.size}" unless grouped.keys.size == 1 # 3.0.3 fails when keys are SortdSets ss1 = SortedSet['fubar'] ss2 = SortedSet['fubar'] warn "expected #{ss1} to equal #{ss2}" unless ss1 == ss2 grouped = { 'a' => ss1, 'b' => ss2 }.group_by { |_, v| v } puts "grouped by SortedSets: #{grouped}" warn "expected 1 key in hash grouped by SortedSets, got #{grouped.keys.size}" unless grouped.keys.size == 1 ``` prints this under 2.7.1: ``` 2.7.1 grouped by Sets: {#<Set: {"fubar"}>=>[["a", #<Set: {"fubar"}>], ["b", #<Set: {"fubar"}>]]} grouped by SortedSets: {#<SortedSet: {"fubar"}>=>[["a", #<SortedSet: {"fubar"}>], ["b", #<SortedSet: {"fubar"}>]]} ``` but prints this under 3.0.3: ``` 3.0.3 grouped by Sets: {#<Set: {"fubar"}>=>[["a", #<Set: {"fubar"}>], ["b", #<Set: {"fubar"}>]]} grouped by SortedSets: {#<SortedSet: {"fubar"}>=>[["a", #<SortedSet: {"fubar"}>]], #<SortedSet: {"fubar"}>=>[["b", #<SortedSet: {"fubar"}>]]} expected 1 key in hash grouped by SortedSets, got 2 ```