Report Content-Security-Policy problems to honeybadger

Co-authored-by: Christina Chortaria <christinach@users.noreply.github.com>

app/views/layouts/application.html.erb

@@ -34,14 +34,16 @@
     <% else  %>
       <%= javascript_include_tag 'requests/application' %>
     <% end %>
-    <script>window.Global = {"graphql":<%= Global.graphql.to_json.html_safe %>,"figgy":<%= Global.figgy.to_json.html_safe %>}</script>
+    <%= javascript_tag nonce: true do -%>
+      window.Global = {"graphql":<%= Global.graphql.to_json.html_safe %>,"figgy":<%= Global.figgy.to_json.html_safe %>}
+    <% end %>
     <% unless controller.controller_name == "request" %>
       <%= vite_javascript_tag 'application' %>
     <% end %>
     <% unless controller.controller_name == "catalog" && controller.action_name == "show" && @document.alma_record? %>
     <%= javascript_include_tag "https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/MathJax.js?config=TeX-MML-AM_CHTML", async: true %>
     <% end %>
-    <%= javascript_include_tag "https://www.google.com/books/jsapi.js" %>
+    <%= javascript_include_tag "https://www.google.com/books/jsapi.js", nonce: true %>
     <%= csrf_meta_tags %>
     <%= content_for(:head) %>
     <link rel="unapi-server" type="application/xml" title="unAPI" href="/unapi"/>

config/initializers/content_security_policy.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+Rails.application.config.content_security_policy_report_only = true
+# Rails.application.config.content_security_policy_nonce_generator = -> request { SecureRandom.base64(16) }
+
+Rails.application.config.content_security_policy do |policy|
+  policy.default_src :self, :https
+  policy.font_src    :self, :https, :data
+  policy.img_src     :self, :https, :data
+  policy.object_src  :none
+  policy.script_src  :self, :https
+
+  # TODO: Upgrade MathJax to the latest version, using yarn/npm rather than the CDN
+  policy.style_src   :self, "'unsafe-inline'"
+  # policy.style_src   :self, :https
+  # policy.report_uri -> { "https://api.honeybadger.io/v1/browser/csp?api_key=#{ENV['HONEYBADGER_API_KEY']}&report_only=true&env=#{Rails.env}&context[user_id]=#{respond_to?(:current_user) ? current_user&.id : nil}" }
+end