Custom url helper method in presenter causing test error - ruby-on-rails

Question

I'm writing tests for a presenter class and am getting the following error when running them, coming from a custom url helper method.
Error:
PersonPresenterTest#test_0011_should get email icon:
ArgumentError: arguments passed to url_for can't be handled. Please require routes or provide your own implementation
app/helpers/people_helper.rb:4:in `link_fa_to'
app/presenters/base_presenter.rb:14:in `method_missing'
app/presenters/person_presenter.rb:54:in `email_icon'
test/presenters/person_presenter_test.rb:59:in `block in <class:PersonPresenterTest>'
person_presenter_test.rb
class PersonPresenterTest < ActionView::TestCase
add_template_helper(PeopleHelper)
def setup
#person = FactoryGirl.create(:person)
#presenter = PersonPresenter.new(#person, view)
end
test 'should get email icon' do
expected = '<a class="icon-link" href="/people/1"><i class="fa fa-envelope fa-1x"></i></a>'
actual = #presenter.email_icon
assert_equal(expected, actual)
end
end
person_presenter.rb
class PersonPresenter < BasePresenter
presents :person
def email_icon
link_fa_to('envelope fa-1x', person) if person.email.present?
end
end
base_presenter.rb
class BasePresenter
def initialize(object, template)
#object = object
#template = template
end
def self.presents(name)
define_method(name) do
#object
end
end
def method_missing(*args, &block)
#template.send(*args, &block)
end
end
people_helper.rb
module PeopleHelper
def link_fa_to(icon_name, link)
link_to content_tag(:i, '', class: "fa fa-#{icon_name}"), link, class: "icon-link"
end
end
routes.rb
Rails.application.routes.draw do
resources :organisations
resources :people
resources :reset_password, only: [:edit, :update, :new, :index, :create]
resources :dashboards, only: [:index]
resources :users
get 'profile' => 'users#show', as: :profile
controller :sessions do
get 'login' => :new
post 'login' => :create
end
get '/auth/:provider/callback', to: 'sessions#create'
get "sessions/create"
get 'sessions' => "sessions#destroy", as: :logout
root 'sessions#new'
end
I can test presenter methods which use link_to successfully, and would expect methods calling link_fa_to to 'fall' through to the template in the same way. This is only affecting tests, the method works perfectly when running the application.
Any help much appreciated.
edit:
If I remove add_template_helper(PeopleHelper) from person_presenter_test.rb, the error is:
Error:
PersonPresenterTest#test_0011_should get email icon:
NoMethodError: undefined method `link_fa_to' for #<#<Class:0x007fcdb6bb19e0>:0x007fcdb6bb15a8>
Did you mean? link_to
app/presenters/base_presenter.rb:14:in `method_missing'
app/presenters/person_presenter.rb:54:in `email_icon'
test/presenters/person_presenter_test.rb:58:in `block in <class:PersonPresenterTest>'
edit 2:
After updating people_helper.rb to the following in response to Shishir's answer, the error message remains the same:
module PeopleHelper
def link_fa_to(icon_name, link)
link_to link, class: "icon-link" do
content_tag(:i, '', class: "fa fa-#{icon_name}")
end
end
end

Answer 1

The method content_tag returns a string (actually it's an ActiveSupport::SafeBuffer, but you can handle it like a string), so that's not your problem.
It seems that you are calling your helper method with an instance of ActiveRecord::Base instead of an url:
link_fa_to('envelope fa-1x', person) if person.email.present?
vs:
def link_fa_to(icon_name, link)
link_to content_tag(:i, '', class: "fa fa-#{icon_name}"), link, class: "icon-link"
end
You could try to update your code to something like this:
link_fa_to('envelope fa-1x', person_path(person)) if person.email.present?

Answer 2

The syntax of link_to you are using doesn't accept content_tag as parameter. It only accepts string.
link_to content_tag(:i, '', class: "fa fa-#{icon_name}"), link, class: "icon-link"
Try
link_to link do
content_tag(:i, '', class: "fa fa-#{icon_name}")
end