Flag customer as dunning campaign completed...

... on dunning campaign attempt execution when customer last attempt
count reaches dunning campaign max attempts.

Also, use customer dunning_campaign_completed? as guard clause instead
of comparing the number of attempts executed against the campaign max
attempts

app/services/dunning_campaigns/process_attempt_service.rb

@@ -16,7 +16,7 @@ def call
       return result unless applicable_dunning_campaign?
       return result unless dunning_campaign_threshold_reached?
       return result unless days_between_attempts_passed?
-      return result if dunning_campaign_completed?
+      return result if customer.dunning_campaign_completed?
 
       ActiveRecord::Base.transaction do
         payment_request_result = PaymentRequests::CreateService.call(
@@ -30,6 +30,7 @@ def call
 
         customer.increment(:last_dunning_campaign_attempt)
         customer.last_dunning_campaign_attempt_at = Time.zone.now
+        customer.dunning_campaign_completed = last_dunning_campaign_attempt?
         customer.save!
 
         result.customer = customer
@@ -64,7 +65,7 @@ def days_between_attempts_passed?
       (customer.last_dunning_campaign_attempt_at + dunning_campaign.days_between_attempts.days).past?
     end
 
-    def dunning_campaign_completed?
+    def last_dunning_campaign_attempt?
       customer.last_dunning_campaign_attempt >= dunning_campaign.max_attempts
     end
 

spec/services/dunning_campaigns/process_attempt_service_spec.rb

@@ -68,9 +68,28 @@
 
     it "updates customer last dunning attempt data" do
       freeze_time do
-        expect { result }
-          .to change(customer.reload, :last_dunning_campaign_attempt).by(1)
-          .and change(customer.reload, :last_dunning_campaign_attempt_at).to(Time.zone.now)
+        expect { result && customer.reload }
+          .to change(customer, :last_dunning_campaign_attempt).by(1)
+          .and change(customer, :last_dunning_campaign_attempt_at).to(Time.zone.now)
+          .and not_change(customer, :dunning_campaign_completed).from(false)
+      end
+    end
+
+    context "when dunning campaign max attemp is reached" do
+      let(:customer) do
+        create(
+          :customer,
+          organization:,
+          currency:,
+          last_dunning_campaign_attempt: dunning_campaign.max_attempts - 1,
+          last_dunning_campaign_attempt_at: dunning_campaign.days_between_attempts.days.ago,
+          dunning_campaign_completed: false
+        )
+      end
+
+      it "updates customer's dunning campaign completed flag" do
+        expect { result && customer.reload }
+          .to change(customer, :dunning_campaign_completed).to(true)
       end
     end
 
@@ -117,13 +136,13 @@
       end
     end
 
-    context "when the customer reaches dunning campaign max attempts" do
+    context "when the customer has completed the dunning campaign" do
       let(:customer) do
         create(
           :customer,
           organization:,
           currency:,
-          last_dunning_campaign_attempt: dunning_campaign.max_attempts
+          dunning_campaign_completed: true
         )
       end