Make it possible to configure when subscription termination alert is …

…sent by setting env var (#1575)

* Make it possible to configure when subscription termination alert is sent by setting env var

Co-authored-by: Vincent Pochet <vincent@getlago.com>

app/jobs/clock/subscriptions_to_be_terminated_job.rb

@@ -12,7 +12,7 @@ def perform
         .active
         .where(
           'DATE(subscriptions.ending_at::timestamptz) IN (?)',
-          [(Time.current + 45.days).to_date, (Time.current + 15.days).to_date],
+          sent_at_dates,
         )
         .where('webhooks.id IS NULL OR webhooks.created_at::date != ?', Time.current.to_date)
         .find_each do |subscription|
@@ -21,5 +21,16 @@ def perform
           end
         end
     end
+
+    private
+
+    def sent_at_dates
+      # NOTE: The alert will be sent 15 and 45 days before the subscription is terminated by default.
+      #       You can override the default by setting below env var.
+      #       E.g. LAGO_SUBSCRIPTION_TERMINATION_ALERT_SENT_AT_DAYS=1,15,45 will cause it
+      #       to be sent at 1, 15, 45 days before subscription terminates, respectively.
+      sent_at_days_config = ENV.fetch('LAGO_SUBSCRIPTION_TERMINATION_ALERT_SENT_AT_DAYS', '15,45')
+      sent_at_days_config.split(',').map { |day_string| Time.current + day_string.to_i.days }.map(&:to_date)
+    end
   end
 end

spec/jobs/clock/subscriptions_to_be_terminated_job_spec.rb

@@ -57,6 +57,24 @@
       end
     end
 
+    context 'when current date is 1 day before subscription ending_at' do
+      it 'sends webhook that subscription is going to be terminated but only if config is overridden' do
+        current_date = ending_at - 1.days
+
+        travel_to(current_date) do
+          # First validate that with default config nothing is sent
+          expect { described_class.perform_now }.not_to have_enqueued_job(SendWebhookJob)
+
+          # Now validate that with custom config, it is actually sent
+          stub_const('ENV', 'LAGO_SUBSCRIPTION_TERMINATION_ALERT_SENT_AT_DAYS' => '1,15,45')
+          expect { described_class.perform_now}
+            .to have_enqueued_job(SendWebhookJob)
+            .with('subscription.termination_alert', Subscription)
+            .exactly(:once)
+        end
+      end
+    end
+
     context 'when the same alert webhook had been already triggered on the same day' do
       let(:webhook_alert1) do
         create(