Simplify conditions to render a banner

app/components/shared/banner_component.html.erb

@@ -1,3 +1,5 @@
-<div class="banner" style="background-color:<%= banner.background_color %>;">
-  <%= sanitize link, attributes: %w[href style] %>
-</div>
+<% if banner %>
+  <div class="banner" style="background-color:<%= banner.background_color %>;">
+    <%= sanitize link, attributes: %w[href style] %>
+  </div>
+<% end %>

app/helpers/banners_helper.rb

@@ -1,5 +0,0 @@
-module BannersHelper
-  def has_banners?
-    @banners.present? && @banners.count > 0
-  end
-end

app/views/shared/_banner.html.erb

@@ -1,5 +1,3 @@
-<% if has_banners? || controller.class == Admin::BannersController %>
-  <% banner ||= @banners.sample %>
+<% banner ||= @banners&.sample %>
 
-  <%= render Shared::BannerComponent.new(banner) %>
-<% end %>
+<%= render Shared::BannerComponent.new(banner) %>

spec/components/shared/banner_component_spec.rb

@@ -0,0 +1,15 @@
+require "rails_helper"
+
+describe Shared::BannerComponent, type: :component do
+  it "renders given a banner" do
+    render_inline Shared::BannerComponent.new(create(:banner, title: "Vote now!"))
+
+    expect(page.find(".banner")).to have_content "Vote now!"
+  end
+
+  it "does not render anything given nil" do
+    render_inline Shared::BannerComponent.new(nil)
+
+    expect(page).not_to have_css ".banner"
+  end
+end