improving code readability: 5 simple tips

1_line_breaks_after.rb

#=> better code (with logical line breaks)
def check_out(current_user)
  if cart.count == 0
    return Status.new(false, "empty cart")
  end

  total_price = cart.calculate_total_price

  if current_user.balance < total_price
    return Status.new(false, "not enough money")
  end

  current_user.deduct_balance(total_price)

  return Status.new(true, nil) 
end

1_line_breaks_before.rb

#=> meh code
def check_out(current_user, cart)
  if cart.count == 0
    return Status.new(false, "empty cart")
  end
  total_price = cart.calculate_total_price
  if current_user.balance < total_price
    return Status.new(false, "not enough money")
  end
  current_user.deduct_balance(total_price)
  return Status.new(true, nil) 
end

2_happypath_after.rb

#=> better code (happy path first)
if transaction.is_successful
  handle_success(transaction)
else
  handle_failure(transaction)
end

2_happypath_before.rb

#=> meh code
if transaction.is_failure
  handle_failure(transaction)
else
  handle_success(transaction)
end

3_guard_clause_after.rb

#=> better code (early returns with guard clauses)
def check_out(current_user)
  cart = current_user.cart

  if cart.count == 0
    return Status.new(false, "empty cart")
  end

  if !cart.are_products_available
    return Status.new(false, "some products are unavailable")
  end

  if current_user.balance < total_price
    return Status.new(false, "not enough money")
  end

  current_user.deduct_balance(total_price)

  return Status.new(true, nil) 
end

3_guard_clause_before.rb

#=> meh code
def check_out(current_user)
  cart = current_user.cart
  
  if cart.count > 0
    if !cart.are_products_available
      if current_user.balance >= total_price
        current_user.deduct_balance(total_price)
        return Status.new(true, nil) 
      else
        return Status.new(false, "not enough money")
      end
    else
      return Status.new(false, "some products are unavailable")
    end
  else
    return Status.new(false, "empty cart")
  end
end

4_avoid_variable_assignment_after.rb

#=> better code (avoid reassigning of variables)

#= Method 1 (introduce a new variable)
users = Users.completed_onboarding_form
users_backend = users.where(specialisations: "backend")

#= Method 2 (define it to what we need immediately)
users = Users.completed_onboarding_form
             .where(specialisations: "backend")

4_avoid_variable_assignment_before.rb

#=> meh code
users = Users.completed_onboarding_form
users = users.where(specialisations: "backend")

5_meaningful_name_after.rb

#=> better code (with usage of meaningful names)
def calculate_total_price(price, quantity, discount, shipping)
  (price * quantity) - discount + shipping
end

5_meaningful_name_before.rb

#=> meh code
def cal_tp(p, q, d, s)
  (p * q) - d + s
end

https://adriangohjw.github.io/posts/2020/07/31/writing-readable-code.html