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
  ruby_bug "http://redmine.ruby-lang.org/projects/ruby-18/issues/show?id=117", "1.8.7" 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
end

describe "SortedSet#flatten!" do
  ruby_bug "http://redmine.ruby-lang.org/projects/ruby-18/issues/show?id=117", "1.8.7" 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
  end

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