add solution

Author: dearshrewdwit

Gemfile

@@ -6,3 +6,4 @@ git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 gem "rspec"
 gem "rubocop"
+gem 'timecop'

Gemfile.lock

@@ -31,6 +31,7 @@ GEM
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
     ruby-progressbar (1.10.0)
+    timecop (0.9.1)
     unicode-display_width (1.4.0)
 
 PLATFORMS
@@ -39,6 +40,7 @@ PLATFORMS
 DEPENDENCIES
   rspec
   rubocop
+  timecop
 
 BUNDLED WITH
    1.16.3

_solution/lib/birthday_list.rb

@@ -0,0 +1,43 @@
+require 'date'
+
+class BirthdayList
+  DATE_FORMAT = '%m-%d'
+
+  def initialize
+    @list = []
+  end
+
+  def add(name, date)
+    @list << { name: name, birthday: date }
+  end
+
+  def show
+    @list.each do |bday|
+      puts "#{bday[:name]}: #{bday[:birthday]}"
+    end
+  end
+
+  def check
+    @list.each do |bday|
+      puts "It's #{bday[:name]}'s birthday today! They are #{age(bday)} years old!" if today?(bday)
+    end
+  end
+
+  private
+
+  def age(bday)
+    Time.now.year - Date.parse(bday[:birthday]).year
+  end
+
+  def today?(bday)
+    birthday_date(bday) == today
+  end
+
+  def birthday_date(bday)
+    Date.parse(bday[:birthday]).strftime(DATE_FORMAT)
+  end
+
+  def today
+    Time.now.strftime(DATE_FORMAT)
+  end
+end

_solution/spec/birthday_list_spec.rb

@@ -0,0 +1,50 @@
+require 'birthday_list'
+require 'timecop'
+
+RSpec.describe BirthdayList do
+  # add my friends’ birthdays
+
+  it 'adds a birthday' do
+    birthday_list = BirthdayList.new
+
+    expect(birthday_list.add('Guy Fawkes', "13 April 1570")).to eq [{ name: 'Guy Fawkes', birthday: "13 April 1570" }]
+  end
+
+  it 'adds two birthdays' do
+    birthday_list = BirthdayList.new
+    birthday_list.add('Guy Fawkes', "13 April 1570")
+
+    expect(birthday_list.add('Julie Andrews', "1 October 1935")).to eq [{ name: 'Guy Fawkes', birthday: "13 April 1570" }, { name: 'Julie Andrews', birthday: "1 October 1935" }]
+  end
+
+  # see them all there with their names
+
+  it 'shows all the birthdays' do
+    birthday_list = BirthdayList.new
+    birthday_list.add('Guy Fawkes', "13 April 1570")
+    birthday_list.add('Julie Andrews', "1 October 1935")
+
+    expect { birthday_list.show }.to output("Guy Fawkes: 13 April 1570\nJulie Andrews: 1 October 1935\n").to_stdout
+  end
+
+   # Check who’s birthday it is today
+
+   it 'checks birthdays for a birthday today' do
+     Timecop.freeze(Time.parse('1 October 2018')) do
+
+       birthday_list = BirthdayList.new
+       birthday_list.add('Guy Fawkes', "13 April 1570")
+       birthday_list.add('Julie Andrews', "1 October 1935")
+
+       expect { birthday_list.check }.to output("It's Julie Andrews's birthday today! They are 83 years old!\n").to_stdout
+     end
+   end
+
+   it 'checks birthdays for a birthday - but there are none' do
+     birthday_list = BirthdayList.new
+     birthday_list.add('Guy Fawkes', "13 April 1570")
+     birthday_list.add('Julie Andrews', "1 October 1935")
+
+     expect { birthday_list.check }.not_to output().to_stdout
+   end
+end