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

ruby_version_is "1.9" do
  describe "Kernel#<=>" do
    it "returns 0 if self" do
      obj = Object.new
      obj.<=>(obj).should == 0
    end

    it "returns 0 if self is == to the argument" do
      obj = mock('has ==')
      obj.should_receive(:==).and_return(true)
      obj.<=>(Object.new).should == 0
    end

    it "returns nil if self is eql? but not == to the argument" do
      obj = mock('has eql?')
      obj.should_not_receive(:eql?)
      obj.<=>(Object.new).should be_nil
    end

    it "returns nil if self.==(arg) returns nil" do
      obj = mock('wrong ==')
      obj.should_receive(:==).and_return(nil)
      obj.<=>(Object.new).should be_nil
    end

    it "returns nil if self is not == to the argument" do
      obj = Object.new
      obj.<=>(3.14).should be_nil
    end
  end
end