pager

pager.rb

require "pager/version"
module Pager
  class RandomRecord
    @@count = 0
    def initialize(records=[], random: true, options:{})
        @records = random ? records.shuffle : records
        @@count = 0
    end

    def next_item
      if @@count != (records.size - 1)
        records[@@count += 1]
      end
    end

    def prev_item
        if @@count != 0
          records[@@count -= 1]
        end
    end

    def first_item
        records[0]
    end

    def last_item
        records[records.size - 1]
    end

    private

    attr_accessor :records, :count
  end
end

Rspec

require 'spec_helper'

describe Pager do
  it 'has a version number' do
    expect(Pager::VERSION).not_to be nil
  end

  it 'does first  useful' do
    recs = [1,3,5]
    rpage = Pager::RandomRecord.new(recs, random: false)
    expect(rpage.first_item).to eq(1)
  end

  it 'does last useful' do
    recs = [1,3,5]
    rpage = Pager::RandomRecord.new(recs, random: false)
    expect(rpage.last_item).to eq(5)
  end

  it 'does next useful' do
    recs = [1,3,5]
    rpage = Pager::RandomRecord.new(recs, random: false)
    expect(rpage.next_item).to eq(3)
  end

  it 'does prev useful' do
    recs = [1,3,5]
    rpage = Pager::RandomRecord.new(recs, random: false)

    expect(rpage.next_item).to eq(3)
    expect(rpage.next_item).to eq(5)
    expect(rpage.prev_item).to eq(3)
  end
end