account.rb

class Account

  def initialize(value = 0)
    @deposit = value
    @history = ['Account created with 0 deposit']
  end

  def deposit
    @deposit
  end

  def increase_deposit_by(value)
    @deposit += value
    @history << "deposit increased by #{value}"
  end

  def decrease_deposit_by(value)
    @deposit -= value
    @history << "deposit decreases by #{value}"
  end

  def reset_deposit
    @deposit = 0
    @history << 'deposit reseted'
  end

  def deposit_history
    @history
  end

end

require 'minitest/autorun'
class TestAccount < MiniTest::Unit::TestCase

  def test_addition
    assert_equal 3, 15 % 6
  end

  def test_initial_deposit
    account = Account.new
    assert_equal 0, account.deposit
    # expect(account.deposit).to eq(0)
  end

  def test_initial_deposit_with_given_value
    account = Account.new(3)
    assert_equal 3, account.deposit
  end

  def test_increase_deposit_by
    account = Account.new(0)
    account.increase_deposit_by(2)
    assert_equal 2, account.deposit
    account.increase_deposit_by(1)
    assert_equal 3, account.deposit
  end

  def test_decrease_deposit_by
    account = Account.new(5)
    account.decrease_deposit_by(2)
    assert_equal 3, account.deposit
    account.decrease_deposit_by(-3)
    assert_equal 6, account.deposit
  end

  def test_reset
    account=Account.new(10)
    account.reset_deposit
    assert_equal 0, account.deposit
  end

  def test_deposit_history
    account = Account.new(0)
    account.increase_deposit_by(3)
    account.decrease_deposit_by(2)
    account.reset_deposit
    account.increase_deposit_by(1)
    expected = ['Account created with 0 deposit', 'deposit increased by 3', 'deposit decreases by 2', 'deposit reseted', 'deposit increased by 1']
    assert_equal expected, account.deposit_history
  end


end

# Regeln für TDD
# 1. Erst den Test schreiben
# 2. Nur minimal implentieren, was die Fehlermeldung erwartet