Rollback Tests

test_database.rb

...
  
  def test_rollback_with_transaction
    db = Database.new

    db.set "Bald", "Eagle"
    assert_equal(1, db.count("Eagle"))

    db.begin
    db.set "Golden", "Eagle"
    db.rollback

    assert_equal(1, db.count("Eagle"))
    assert_equal("NULL", db.get("Golden"))
  end

  def test_rollback_no_transaction
    db = Database.new

    assert_equal("No transaction in progress", db.rollback)
  end

...