Agile Web Development with Rails 7.2

When Things Go Wrong

Let’s start by introducing a typo in the source code—one that perhaps is introduced by a misfiring autocorrect function in your favorite editor:

rails72/demo5/app/controllers/say_controller.rb

class SayController < ApplicationController
  def hello
    @time = Time.know
  end

  def goodbye
  end
end

Refresh the following page in your browser: http://localhost:3000/say/hello. You should see something like the following screenshot.

What you see is that Ruby tells you about the error (“undefined method ‘know’”), and Rails shows you the extracted source where the code can be found (Rails.root), the stack ...