let_spec.rb

let_spec.rb

require 'rspec'

class BankAccount
  attr_reader :balance
  def initialize(initial_value = nil)
    @balance = initial_value || 0
  end
  def deposit(amount)
    @balance += amount
  end
end

RSpec.describe BankAccount do
  context 'when account is new' do
    let(:account) { BankAccount.new(0) }

    before { account.deposit(10) }

    specify 'first example' do
      expect(account.balance).to eq(10)
    end

    specify 'second example' do
      expect(account.balance).to eq(10)
    end
  end
end