Ruby-Lab

• Build the Ruby development environment via Visual studio code with extension Ruby
• For the BDD (Behaviour Drive Development) purpose, download and installed RSpec

1. First we created empty class called: Account inside the account.rb

class Account
end

2. Then we created our first test scenario inside the account_spec.rb

The testing target aim for Account class

RSpec.describe Account do
end

3. We need initilize our account object under the constructor

So before we startup our testing case, we need create new account object that passing account identity and balance while account first open

RSpec.describe Account do
  before(:all) do
          @inital_balance = 100_100
          @test_account = Account.new('TestAccount1', @inital_balance)
   end
end

4. Let's run the test case and you might get red light(or failed)

Cause we did not implement constructor inside the account.rb yet

class Account
   def initialize(name, balance = 0)
    @name = name
    @balance = balance
  end
end

5. Now turned back to account_spec.rb and performed the testing, we might get rid of error, means that we got green light

For the next step, started to write the first feature of test case, for exmaple: desposit

RSpec.describe Account do
  before(:all) do
          @inital_balance = 100_100
          @test_account = Account.new('TestAccount1', @inital_balance)
   end
   describe ".desposit" do
       context 'When transaction amount <= 0' do
            it 'Should return intput amount [x] invalid' do
                @trans =  TransactionItem.new(Time.new, -1, DESPOSIT, 'Desposit invalid test')
                @result = @test_account.desposit(@trans)
                expect(@result).to eq INVALIDINPUT
            end
        end
   end
end

6. Again triggered the test case, red light return

Go back to account.rb and implement the detail of desposit method and created the new class TranasctionItem...

class Account
  #....
  def desposit(trans)
      if trans.amount <= 0
        puts "Input amount '#{trans.amount}' invalid"
        return INVALIDINPUT
      end
  end
end

class TransactionItem
  attr_reader :date, :amount, :memo, :code

  def initialize(date, amount, code, memo)
    @date = date
    @amount = amount
    @code = code
    @memo = memo
  end
end

7. Tried to finish the test case and let it become green light, iterator the process till the user requriement all meet:)

Test case -> red light -> implment detail -> green light -> back to test case

• Exmaple of test case that simulate concurrent environment