How do I resolve "Missing host to link to! Please provide the :host parameter"? (RoR)

Question

I'm following the RoR Tutorial and I'm stuck at Listing 9.15

I getting the following error after running 'bundle exec rspec spec/' :

1) Authentication authorization as wrong user submitting a PATCH request to the Users#update action 
     Failure/Error: specify { expect(response).to redirect_to(root_url) }
     ArgumentError:
       Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true
     # ./spec/features/authentication_pages_spec.rb:79:in `block (5 levels) in <top (required)>'

My Authentication test code is:

require 'spec_helper'

describe "Authentication", type: :request do

  subject { page }


  describe "signin page" do
    before { visit signin_path }

    it { should have_content('Sign in') }
    it { should have_title('Sign in') }
  end

  describe "signin" do
    before { visit signin_path }

    describe "with invalid information" do
      before { click_button "Sign in" }

      it { should have_title('Sign in') }
      it { should have_selector('div.alert.alert-error', text: 'Invalid') }

      describe "after visiting another page" do
        before { click_link "Home" }
        it { should_not have_selector('div.alert.alert-error') }
      end

    end

    describe "with valid information" do
      let(:user) { FactoryGirl.create(:user) }
      before { sign_in user }

      #it { should have_title(user.name) }
      it { should have_link('Profile',     href: user_path(user)) }
      it { should have_link('Settings',    href: edit_user_path(user)) }
      it { should have_link('Sign out',    href: signout_path) }
      it { should_not have_link('Sign in', href: signin_path) }

      describe "followed by signout" do
        before { click_link "Sign out" }
        it { should have_link('Sign in') }
      end
    end
  end

  describe "authorization" do

    describe "for non-signed-in users" do
      let(:user) { FactoryGirl.create(:user) }

      describe "in the Users controller" do

        describe "visiting the edit page" do
          before { visit edit_user_path(user) }
          it { should have_title('Sign in') }
        end

        describe "submitting to the update action" do
          before { patch user_path(user) }
          specify { expect(response).to redirect_to(signin_path) }
        end
      end
    end

    describe "as wrong user" do
      let(:user) { FactoryGirl.create(:user) }
      let(:wrong_user) { FactoryGirl.create(:user, email: "[email protected]") }
      before { sign_in user, no_capybara: true }

      describe "visiting Users#edit page" do
        before { visit edit_user_path(wrong_user) }
        #it { should_not have_title(full_title('Edit user')) }
      end

      describe "submitting a PATCH request to the Users#update action" do
        before { patch user_path(wrong_user) }
        specify { expect(response).to redirect_to(root_url) }
      end
    end

  end
end

I don't know how to resolve this issue so the test passes. How do I resolve it? Could someone explain what's going wrong? (According to the tutorial the test should be passing).

Answer 1

In the end I just used:

root_path

instead of:

root_url

Answer 2

The problem may be that you have not defined default_host for test environment. Define default_host inside config/environments/test.rb like this:

config.action_mailer.default_url_options = {:host => "localhost:3000"}