RSpec - Capybara and Puma - Routing Error - ruby-on-rails

Question

I'm trying to use Capybara as a front-end test suite (Vue) and I'm getting the following error from Puma:
Failure/Error: raise ActionController::RoutingError, "No route matches [#{env['REQUEST_METHOD']}] #{env['PATH_INFO'].inspect}"
ActionController::RoutingError:
No route matches [GET] "/login"
What is the cause of this and how can I fix this? Is it something to do with the config? Let me know if I should include more code in my question.
rails_helper.rb:
ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
abort("The Rails environment is running in production mode!") if Rails.env.production?
require 'spec_helper'
require 'rspec/rails'
require "pundit/rspec"
require "capybara/rails"
require "capybara/rspec"
require "capybara/poltergeist"
require 'database_cleaner'
require 'factory_girl'
require 'shoulda/matchers'
require "paperclip/matchers"
require 'support/spec_helpers/warden_controller_helpers'
require 'webmock/rspec'
require 'support/spec_helpers/webmock_helper'
Capybara.javascript_driver = :poltergeist
login_spec.rb:
require 'rails_helper'
RSpec.feature "User login", type: :feature, js: true do
before :each do
#user = User.create!(
first_name: "Bob",
last_name: "Brown",
email: "bob#email.com",
password: "bob1",
has_accepted_terms: true
)
end
scenario "User logs in with correct credentials" do
visit root_path
save_screenshot
click_on 'Log In'
sleep 1
save_screenshot
end
end

Answer 1

So if I run the dev server and go to 'localhost:3000 (which is basically what you're telling Capybara to do) then there is a broken 'Log In' link on the page that points to app.localhost:3000/login which the app doesn't handle. This is because visiting a URL without the app subdomain uses the application.html.haml layout which includes no JS (and therefore no Vue router to handle the /login path). If however I go to app.localhost:3000 in the browser then there's a page with a working Log In link since all the JS is loaded on that page (including the Vue router) because it uses the app.html.haml layout (BaseController)
You need to fix the main homepage link to function correctly and/or configure Capybara to connect to the app subdomain by default
Capybara.app_host = 'http://app.localhost' # hostname with ‘app’ sub domain that resolves to interface the AUT is being run on
Capybara.always_include_port = true
Basically Capybaras telling you your apps main page is broken because it is broken.