Easily use view helpers in specs with `h.number_to_currency`

spec_view_helpers.rb

module ViewHelpers
  def h
    ViewHelper.instance
  end

  class ViewHelper
    include Singleton
    include ActionView::Helpers::NumberHelper
    include ApplicationHelper
  end
end

RSpec.configure do |config|
  config.include ViewHelpers
end

xample_spec.rb

require 'rails_helper'

feature 'some feature' do
  scenario 'can see the percentage' do
    savings = # Use rails view helpers freely in spec!
      h.number_to_percentage(3.00, strip_insignificant_zeros: true)
    expect(savings).to eq "3%"
  end
end