news_link_spec.rb

require "rails_helper"

describe "news_link/index.html.erb" do
  context "when there are additional pages" do
    it "shows the 'Show more' link" do
      news_links_page = build_news_link_page(has_more_pages: true)

      render_page(news_links_page)

      expect(rendered).to have_link('Show More')
    end
  end

  context "when there are not additional pages" do
    it "does not show the 'Show more' link" do
      # explicitly set false here, even though builder method has default. We
      # want the test to be self contained and expressive.
      news_links_page = build_news_link_page(has_more_pages: false)

      render_page(news_links_page)

      expect(rendered).to have_link('Show More')
    end
  end

  def build_news_link_page(objects: [], has_more_pages: false)
    double('NewsLinksPage',
      objects: objects,
      has_more_pages?: has_more_pages,
      next_page: double('Page', to_param: '1')
    )
  end

  def render_page(news_links_page)
    assign(:news_links_page, news_links_page)
    render
  end
end