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

describe "Enumerable#drop" do
  ruby_version_is '1.8.7' do
    before :each do
      @enum = EnumerableSpecs::Numerous.new(3, 2, 1, :go)
    end

    it "requires exactly one argument" do
      lambda{ @enum.drop{} }.should raise_error(ArgumentError)
      lambda{ @enum.drop(1, 2){} }.should raise_error(ArgumentError)
    end

    describe "passed a number n as an argument" do
      it "raise ArgumentError if n < 0" do
        lambda{ @enum.drop(-1) }.should raise_error(ArgumentError)
      end

      it "tries to convert n to an Integer using #to_int" do
        @enum.drop(2.3).should == [1, :go]

        obj = mock('to_int')
        obj.should_receive(:to_int).and_return(2)
        @enum.drop(obj).should == [1, :go]
      end

      it "returns [] for empty enumerables" do
        EnumerableSpecs::Empty.new.drop(0).should == []
        EnumerableSpecs::Empty.new.drop(2).should == []
      end

      it "returns [] if dropping all" do
        @enum.drop(5).should == []
        EnumerableSpecs::Numerous.new(3, 2, 1, :go).drop(4).should == []
      end

      it "raises a TypeError when the passed n can be coerced to Integer" do
        lambda{ @enum.drop("hat") }.should raise_error(TypeError)
        lambda{ @enum.drop(nil) }.should raise_error(TypeError)
      end

    end
  end
end
