Add preview for authorship notifier

Author: rsmithlal

spec/mailers/previews/better_together/authorship_mailer_preview.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module BetterTogether
+  # Preview at /rails/mailers/better_together/authorship_mailer
+  class AuthorshipMailerPreview < ActionMailer::Preview
+    include FactoryBot::Syntax::Methods
+    include BetterTogether::ApplicationHelper
+
+    # Preview this email at
+    # /rails/mailers/better_together/authorship_mailer/authorship_changed_notification
+    def authorship_changed_notification
+      host_platform || create(:platform, :host)
+
+      actor = create(:user, :confirmed)
+      recipient = create(:user, :confirmed)
+      # Use build to avoid Elasticsearch callbacks on BetterTogether::Page
+      page = build(:page)
+
+      BetterTogether::AuthorshipMailer
+        .with(page: page,
+              recipient: recipient.person,
+              action: 'added',
+              actor_name: actor.person.name)
+        .authorship_changed_notification
+    end
+  end
+end