require_relative '../../../spec_helper'

ruby_version_is ""..."3.0" do
  require 'set'

  # Note: Flatten make little sens on sorted sets, because SortedSets are not (by default)
  # comparable. For a SortedSet to be both valid and nested, we need to define a comparison operator:
  module SortedSet_FlattenSpecs
    class ComparableSortedSet < SortedSet
      def <=>(other)
        return puts "#{other} vs #{self}" unless other.is_a?(ComparableSortedSet)
        to_a <=> other.to_a
      end
    end
  end

  describe "SortedSet#flatten" do
    it "returns a copy of self with each included SortedSet flattened" do
      klass = SortedSet_FlattenSpecs::ComparableSortedSet
      set = klass[klass[1,2], klass[3,4], klass[5,6,7], klass[8]]
      flattened_set = set.flatten

      flattened_set.should_not equal(set)
      flattened_set.should == klass[1, 2, 3, 4, 5, 6, 7, 8]
    end
  end

  describe "SortedSet#flatten!" do
    it "flattens self" do
      klass = SortedSet_FlattenSpecs::ComparableSortedSet
      set = klass[klass[1,2], klass[3,4], klass[5,6,7], klass[8]]
      set.flatten!
      set.should == klass[1, 2, 3, 4, 5, 6, 7, 8]
    end

    it "returns self when self was modified" do
      klass = SortedSet_FlattenSpecs::ComparableSortedSet
      set = klass[klass[1,2], klass[3,4]]
      set.flatten!.should equal(set)
    end

    it "returns nil when self was not modified" do
      set = SortedSet[1, 2, 3, 4]
      set.flatten!.should be_nil
    end
  end
end