CLDC-1618 Add analytics script inclusion tests

spec/views/layouts/application_layout_spec.rb

@@ -0,0 +1,57 @@
+require "rails_helper"
+
+RSpec.describe "layouts/application" do
+  shared_examples "analytics cookie elements" do |banner:, scripts:|
+    define_negated_matcher :not_match, :match
+
+    it "#{banner ? 'includes' : 'omits'} the cookie banner" do
+      banner_text = "We’d like to use analytics cookies so we can understand how you use the service and make improvements."
+      if banner
+        expect(rendered).to match(banner_text)
+      else
+        expect(rendered).not_to match(banner_text)
+      end
+    end
+
+    it "#{scripts ? 'includes' : 'omits'} the analytics scripts" do
+      gtm_script_tag = /<script.*googletagmanager/
+      gtm_iframe_tag = /<iframe.*googletagmanager/
+      if scripts
+        expect(rendered).to match(gtm_script_tag).and match(gtm_iframe_tag)
+      else
+        expect(rendered).to not_match(gtm_script_tag).and not_match(gtm_iframe_tag)
+      end
+    end
+  end
+
+  context "with no cookie set" do
+    before do
+      cookies[:accept_analytics_cookies] = nil
+      render
+    end
+
+    include_examples "analytics cookie elements", banner: true, scripts: false
+
+    it "sets window.analyticsScript for the JS to refer to if the user accepts" do
+      expect(rendered).to match(/window\.analyticsScript = "https:\/\/www\.googletagmanager\.com\/gtag\/js\?id=G-[\w\d]+"/)
+    end
+  end
+
+  context "with analytics accepted" do
+    before do
+      cookies[:accept_analytics_cookies] = "on"
+      render
+    end
+
+    include_examples "analytics cookie elements", banner: false, scripts: true
+  end
+
+  context "with analytics rejected" do
+    before do
+      cookies[:accept_analytics_cookies] = "off"
+      render
+    end
+
+    include_examples "analytics cookie elements", banner: false, scripts: false
+  end
+end