Add basic coverage for `WebhookService` class (#29331)

spec/services/webhook_service_spec.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe WebhookService do
+  describe '#call' do
+    context 'with a relevant event webhook' do
+      let!(:report) { Fabricate(:report) }
+      let!(:webhook) { Fabricate(:webhook, events: ['report.created']) }
+
+      it 'finds and delivers webhook payloads' do
+        expect { subject.call('report.created', report) }
+          .to enqueue_sidekiq_job(Webhooks::DeliveryWorker)
+          .with(
+            webhook.id,
+            anything
+          )
+      end
+    end
+
+    context 'without any relevant event webhooks' do
+      let!(:report) { Fabricate(:report) }
+
+      it 'does not deliver webhook payloads' do
+        expect { subject.call('report.created', report) }
+          .to_not enqueue_sidekiq_job(Webhooks::DeliveryWorker)
+      end
+    end
+  end
+end