require "spec_helper"
require "hamster/vector"

describe Hamster::Vector do
  [:reduce, :inject, :fold, :foldr].each do |method|
    describe "##{method}" do
      [
        [[], 10, 10],
        [[1], 10, 9],
        [[1, 2, 3], 10, 4],
      ].each do |values, initial, expected|

        describe "on #{values.inspect}" do
          before do
            @vector = Hamster.vector(*values)
          end

          describe "with an initial value of #{initial}" do
            describe "and a block" do
              it "returns #{expected.inspect}" do
                @vector.send(method, initial) { |memo, item| memo - item }.should == expected
              end
            end

            describe "and no block" do
              it "returns the memo" do
                @vector.send(method, initial).should == initial
              end
            end
          end
        end
      end

      [
        [[], nil],
        [[1], 1],
        [[1, 2, 3], -4],
      ].each do |values, expected|

        describe "on #{values.inspect}" do
          before do
            @vector = Hamster.vector(*values)
          end

          describe "with no initial value" do
            describe "and a block" do
              it "returns #{expected.inspect}" do
                @vector.send(method) { |memo, item| memo - item }.should == expected
              end
            end

            describe "and no block" do
              it "returns nil" do
                @vector.send(method).should be_nil
              end
            end
          end
        end
      end
    end
  end
end