nil:NilClass when ByeBug reports expected outcome - ruby-on-rails

Question

I am trying to access my dirts/index page, but I am getting this error shown in the picture below.
So I put a byebug in the #total_trip_miles to see what is going on:
class Driver < ApplicationRecord
has_many :dirts
validates :name, presence: true, uniqueness: true
def total_trip_miles
byebug
collect_trip_miles.round.to_s
end
def average_speed
total_distance = collect_trip_miles
total_rate = collect_trip_seconds
((total_distance/total_rate)*3600).round
end
def collect_trip_miles
dirts.map do |trip|
trip.distance.to_f
end.inject(:+)
end
def collect_trip_seconds
seconds = []
dirts.map do |trip|
seconds << trip.change_in_time(trip.start_time, trip.end_time)
end
seconds.inject(:+)
end
end
When I call the collect_trip_miles.round.to_s from byebug I get "55", which is exactly what I want to pass my spec:
I call the method from #drivers in the dirt/index.html.erb:
<ul id="trips">
<% drivers.each do |driver| %>
<li>
<article class="driver">
<header>
<h2><%= show_name_of(driver) %></h2>
</header>
<p>
<%= "#{show_total_miles_of(driver)} Miles" %>
</p>
<table>
</table>
<footer>
</footer>
</article>
</li>
<% end %>
</ul>
And those methods are called from my app/helpers/dirts_helper.rb
module DirtsHelper
def show_name_of(driver)
the_driver(driver).name.capitalize
end
def show_total_miles_of(driver)
the_driver(driver).total_trip_miles
end
def the_driver(driver)
Driver.find(driver.first)
end
def drivers
#driver_store = {}
#drivers.each_with_index do |driver, dirts|
#driver_store[driver.id] = driver.dirts
end
#driver_store
end
end
And then the controller action comes from app/controllers/dirts_controller.rb
class DirtsController < ApplicationController
def index
#drivers = Driver.all
end
end
Based on what I've described and shown evidence for, is there some-super-obvious-I-should-be-ashamed-of-myself reason why my driver model's methods are blowing up in my localhost but debugging is reporting as expected?

Answer 1

Could it be this?
def the_driver(driver)
Driver.find(driver.first)
end
You are iterating drivers.each do |driver| in your view, do when you pass it into show_total_miles_of and then subsequently the_driver, you should not have to find it, as you are already dealing with a single instance of an object.

Answer 2

I made the mistake of not guarding against nil in my collection of drivers, some of them don't have any trip miles. So, calling #round on nothing is throwing an error but it works in ByeBug because that is just capturing one item in the collection that just so happens to have miles as well and so calling #round on the Float works.