ruby( ActiveSupportあり )で、誕生日の前後一週間かどうかを判定するメソッドを実装してください〜

birthday_around_a_week_challenge.rb

# 準備
#   `gem i activesupport`
#   `gem i rspec`
# 実行
#   `rspec birthday_around_a_week_challenge.rb`

# 実装
require 'active_support'
require 'active_support/core_ext'
# require 'byebug'

class BirthDay
  def self.around_a_week?(birthday)
    # TODO: 実装！
  end
end

# spec_helper
require 'rspec'
require 'active_support/testing/time_helpers'

RSpec.configure do |config|
  config.include ActiveSupport::Testing::TimeHelpers
end

# spec
RSpec.describe BirthDay do
  describe 'around_a_week?' do
    subject(:around_a_week?) { travel_to(today.to_time) { BirthDay.around_a_week?(birthday) } }

    context '年をまたがない場合' do
      let!(:birthday){ '1985-05-26 0:00'.to_time }

      context '7日前' do
        let!(:today) { '2019-5-19 00:00' }
        it { expect(around_a_week?).to eq true }
      end

      context '8日前' do
        let!(:today) { '2019-5-18 23:59' }
        it { expect(around_a_week?).to eq false }
      end

      context '7日後' do
        let!(:today) { '2019-6-2 23:59' }
        it { expect(around_a_week?).to eq true }
      end

      context '8日後' do
        let!(:today) { '2019-6-3 00:00' }
        it { expect(around_a_week?).to eq false }
      end
    end

    context '年をまたぐ場合' do
      context '年末の場合' do
        let(:birthday){ '1985-12-27 0:00'.to_time }

        context '7日前' do
          let!(:today) { '2019-12-20 00:00' }
          it { expect(around_a_week?).to eq true }
        end

        context '8日前' do
          let!(:today) { '2019-12-19 23:59' }
          it { expect(around_a_week?).to eq false }
        end

        context '7日後' do
          let!(:today) { '2020-1-3 23:59' }
          it { expect(around_a_week?).to eq true }
        end

        context '8日後' do
          let!(:today) { '2020-1-4 00:00' }
          it { expect(around_a_week?).to eq false }
        end
      end

      context '年始の場合' do
        let(:birthday){ '1985-01-03 0:00'.to_time }

        context '7日前' do
          let!(:today) { '2019-12-27 00:00' }
          it { expect(around_a_week?).to eq true }
        end

        context '8日前' do
          let!(:today) { '2019-12-26 23:59' }
          it { expect(around_a_week?).to eq false }
        end

        context '7日後' do
          let!(:today) { '2020-1-10 23:59' }
          it { expect(around_a_week?).to eq true }
        end

        context '8日後' do
          let!(:today) { '2020-1-11 00:00' }
          it { expect(around_a_week?).to eq false }
        end
      end
    end
  end
end