Session_2_Quiz.md

Session 2

These are the code examples for the Clean Code Quiz.

For each example, look at the code and list bad smells. If you have an idea, describe how you would improve the code as well. Most - but not all - smells are listed in the Refactoring book. If you can, use Fowler's names for the smells.

Example 1

var d; // elapsed time in days

Example 2

// Subtract discount from price.
finalPrice = (numItems * itemPrice) - min(5, numItems) * itemPrice * 0.1

Example 3

def check_user_array(user):
   if user['data']['name']['first']:
       first_name = user['data']['name']['first']
   else:
       if user['data']['name']['last']:
           return user['data']['name']['last']
   if user['data']['name']['last']:
       last_name = user['data']['name']['last']
       if user['data']['name']['first']:
           return first_name + ' ' + last_name
   else:
       if user['data']['name']['first']:
           return first_name
       else:
           return ''

Example 4

function calculateTotal(priceA, priceB, taxRate) {
    let total = priceA
    total += priceB
    total *= taxRate
    return total
}

Example 5

def log_items_and_send_receipts(items, email_address):
   total_price = 0
   for item in items:
       price = item.price * 1.16
       total_price += price
   
   for item in items:
       print('Item ID:', item.id)
       print('Item Name:', item.name)
       print('Item price:', item.price)
   print('Email: ' + email_address)
   print('Total', total_price)

   email_message = 'New Order! Total price' + str(total_price)
   server = smtplib.SMTP(smtp_server, port)
   server.starttls(context = context)  # Secure the connection
   server.login(sender_email, password)
   server.sendmail(sender_email, email_address, email_message)

Example 6

GAME_BOARD = [...] # list of cells, each cell is a dict

def get_flagged_cells() -> List[any]:
   flagged_cells = []
   for cell in GAME_BOARD:
       if cell['STATUS_VALUE'] == FLAGGED:
           flagged_cells.append(cell)

   return flagged_cells

Example 7

response = server.Call(request)
 
if response.GetStatus() == RPC.OK:
  if response.GetAuthorizedUser():
    if response.GetEnc() == 'utf-8':
      if response.GetRows():
        vals = [ParseRow(r) for r in response.GetRows()]
        avg = sum(vals) / len(vals)
        return avg, vals
      else:
        raise EmptyError()
    else:
      raise AuthError('unauthorized')
  else:
    raise ValueError('wrong encoding')
else:
  raise RpcError(response.GetStatus())

Example 8: Bonus

Is this code clean? Why/why not?

Explanation of what this code does

float InvSqrt(float x){
    float xhalf = 0.5f * x;
    int i = *(int*)&x;            // store floating-point bits in integer
    i = 0x5f3759df - (i >> 1);    // initial guess for Newton's method
    x = *(float*)&i;              // convert new bits into float
    x = x*(1.5f - xhalf*x*x);     // One round of Newton's method
    return x;
}