oystercard.rb

class Oystercard

  MAXIMUM_BALANCE = 90

  attr_reader :balance, :top_up
  attr_accessor :in_journey

  def initialize
    @balance = 0
    @in_journey = false
  end

  def top_up(amount)
    raise "Error. You cannot top up in excess of £#{MAXIMUM_BALANCE}." if amount + @balance > MAXIMUM_BALANCE
    @balance += amount
  end

  def deduct(amount)
    @balance -= amount
  end

  def in_journey?
    @in_journey = false
  end

  def touch_in
    @in_journey = true
  end

  def touch_out
    @in_journey = false
  end

end

#RSPEC TEST BELOW

require 'oystercard'

describe Oystercard do

  context "when initializing" do
    it "has an initial balance of 0" do
      expect(subject.balance).to eq(0)
    end
  end

  context "when topping up @balance" do
    it "#top_up takes an amount argument" do
      expect(subject).to respond_to(:top_up).with(1).argument
    end

    it "#top_up increments the balance" do
      expect{subject.top_up(10)}.to change{subject.balance}.by(10)
    end

    it "#top_up throws an exception if balance exceed £90" do
      maximum_balance = Oystercard::MAXIMUM_BALANCE
      subject.top_up(maximum_balance)
      expect{ subject.top_up(1) }.to raise_error("Error. You cannot top up in excess of £#{maximum_balance}.")
    end
  end

  context "when deducting @balance" do
    it "#deduct decrements the balance by the amount specified" do
      expect{subject.deduct(10)}.to change{subject.balance}.by(-10)
    end
  end

  context "when touching in and touching out" do
    it "#in_journey? returns if a journey is in progress" do
      expect(subject).not_to be_in_journey
    end
####--------------[THIS EXAMPLES SEEMS TO FAIL]-------------
    it "#touch_in returns that a journey is in progress - true " do
      subject.touch_in
      expect(subject).to be_in_journey
    end
####---------------------------------------------------------
    it "#touch_out returns that a journey is no longer in progress - false" do
      subject.touch_out
      expect(subject).not_to be_in_journey
    end
  end
end