To get to the crux of this question right away: Does LiveView always do a first render without any assigns?

So I’m using a struct as one of my assigns. Imagine I’m the url being something like https://mydomain.com/some_id:

defmodule MyAppWeb.HomeLive do
  use MyAppWeb, :live_view

  @default_assigns [
    record: nil, # The default here will never be used, hence `nil`.  I tried giving it a default and it doesn't solve my problem.
    another_key: "that has a dynamic value but needs a default"
  ]

  def mount(%{"record_id" => record_id}, _session, socket) do
    record = Records.find_record(record_id)
    {:ok, assign(socket, @default_assigns |> Keyword.replace!(:record, record))}
  end
end

Then in my template:

<div><%= @record.some_key %></div>

No matter what, even though my page loads seemingly without a hitch, I always get an error that “nil.some_key is not a function”.

I can, of course, fix this with:

<div<%= @record && @record.some_key %></div>

but I’m confused about the lifecycle here… does the template always render once without been passed any assigns? OR am I just doing something completely wrong?

Thanks!