require File.expand_path('../../../spec_helper', __FILE__)

ruby_version_is "1.9" do
  describe "Hash#flatten" do

    before(:each) do
      @h = {:plato => :greek,
            :witgenstein => [:austrian, :british],
            :russell => :welsh}
    end

    it "returns an Array" do
      new_hash.flatten.should be_an_instance_of(Array)
    end

    it "returns an empty Array for an empty Hash" do
      new_hash.flatten.should == []
    end

    it "sets each even index of the Array to a key of the Hash" do
      a = @h.flatten
      a[0].should == :plato
      a[2].should == :witgenstein
      a[4].should == :russell
    end

    it "sets each odd index of the Array to the value corresponding to the previous element" do
      a = @h.flatten
      a[1].should == :greek
      a[3].should == [:austrian, :british]
      a[5].should == :welsh
    end

    it "does not recursively flatten Array values when called without arguments" do
      a = @h.flatten
      a[3].should == [:austrian, :british]
    end

    it "does not recursively flatten Hash values when called without arguments" do
      @h[:russell] = {:born => :wales, :influenced_by => :mill }
      a = @h.flatten
      a[5].should_not == {:born => :wales, :influenced_by => :mill }.flatten
    end

    it "recursively flattens Array values when called with an argument >= 2" do
      a = @h.flatten(2)
      a[3].should == :austrian
      a[4].should == :british
    end

    it "recursively flattens Array values to the given depth" do
      @h[:russell] = [[:born, :wales], [:influenced_by, :mill]]
      a = @h.flatten(2)
      a[6].should == [:born, :wales]
      a[7].should == [:influenced_by, :mill]
    end

    it "raises an TypeError if given a non-Integer argument" do
      lambda do
        @h.flatten(Object.new)
      end.should raise_error(TypeError)
    end
  end
end