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

ruby_version_is "1.8.7" do
  describe "Enumerable#one?" do
    describe "when passed a block" do
      it "returns true if block returns true once" do
        [:a, :b, :c].one? { |s| s == :a }.should be_true
      end

      it "returns false if the block returns true more than once" do
        [:a, :b, :c].one? { |s| s == :a || s == :b }.should be_false
      end

      it "returns false if the block only returns false" do
        [:a, :b, :c].one? { |s| s == :d }.should be_false
      end

      ruby_version_is ""..."1.9" do
        it "gathers whole arrays as elements when each yields multiple" do
          multi = EnumerableSpecs::YieldsMulti.new
          multi.one? {|e| e == [1, 2] }.should be_true
        end
      end

      ruby_version_is "1.9" do
        it "gathers initial args as elements when each yields multiple" do
          multi = EnumerableSpecs::YieldsMulti.new
          multi.one? {|e| e == 1 }.should be_true
        end
      end

      it "yields multiple arguments when each yields multiple" do
        multi = EnumerableSpecs::YieldsMulti.new
        yielded = []
        multi.one? {|e, i| yielded << [e, i] }
        yielded.should == [[1, 2], [3, 4]]
      end
    end

    describe "when not passed a block" do
      it "returns true if only one element evaluates to true" do
        [false, nil, true].one?.should be_true
      end

      it "returns false if two elements evaluate to true" do
        [false, :value, nil, true].one?.should be_false
      end

      it "returns false if all elements evaluate to false" do
        [false, nil, false].one?.should be_false
      end

      it "gathers whole arrays as elements when each yields multiple" do
        multi = EnumerableSpecs::YieldsMultiWithSingleTrue.new
        multi.one?.should be_false
      end
    end
  end
end