Secret Diary demo

secret_diary_demo.rb

# -------------------------------------------------------
# 
# spec/diary_spec.rb

describe 'Diary' do
  it 'can add entry' do
    diary = Diary.new

    expect(diary.add('hello')).to eq :ok
  end

  it 'can read entries' do
    diary = Diary.new
    diary.add('hello')
    diary.add('world')

    expect(diary.read).to eq "hello\nworld"
  end
end

# -------------------------------------------------------
# 
# lib/diary.rb

class Diary
  def initialize
    @entries = []
  end

  def add(str)
    @entries << str
    :ok
  end

  def read
    @entries.join("\n")
  end
end

# -------------------------------------------------------
# 
# spec/secret_diary_spec.rb

describe 'A secret diary' do
  describe 'can be locked' do
    it 'starts locked' do
      diary = test_double
      secret_diary = SecretDiary.new(diary)
      expect(secret_diary.locked?).to eq true
    end

    it 'can be unlocked' do
      diary = test_double
      secret_diary = SecretDiary.new(diary)
      secret_diary.unlock
      expect(secret_diary.locked?).to eq false
    end

    it 'can be locked' do
      diary = test_double
      secret_diary = SecretDiary.new(diary)
      secret_diary.unlock
      secret_diary.lock

      expect(secret_diary.locked?).to eq true
    end
  end

  describe 'when locked' do
    it 'can not add entry' do
      diary = test_double
      secret_diary = SecretDiary.new(diary)

      expect(secret_diary.add('hello')).to eq 'Sorry, diary is locked!'
    end

    it 'can not read entries' do
      diary = test_double
      secret_diary = SecretDiary.new(diary)

      expect(secret_diary.read).to eq 'Sorry, diary is locked!'
    end
  end

  describe 'when unlocked' do
    it 'can add entry' do
      diary = test_double
      allow(diary).to receive(:add) { :ok }
      
      secret_diary = SecretDiary.new(diary)
      secret_diary.unlock

      expect(secret_diary.add('hello')).to eq :ok
    end

    it 'can read entries' do
      diary = test_double
      allow(diary).to receive(:add) { :ok }
      allow(diary).to receive(:read) { "hello\nworld" }

      secret_diary = SecretDiary.new(diary)
      secret_diary.unlock
      secret_diary.add('hello')
      secret_diary.add('world')

      expect(secret_diary.read).to eq "hello\nworld"
    end
  end
end

# -------------------------------------------------------
# 
# lib/secret_diary.rb

require_relative 'diary.rb'

class SecretDiary
  def initialize(diary)
    @status = :locked
    @diary = diary
  end

  def add(str)
    return "Sorry, diary is locked!" if locked?

    @diary.add(str)
  end

  def read
    return "Sorry, diary is locked!" if locked?

    @diary.read
  end

  def unlock
    @status = :unlocked
  end

  def lock
    @status = :locked
  end

  def locked?
    @status == :locked
  end
end