FIX: Exception with campaign refresh data job (#222)

Depending on the invoices in stripe there could be some nil values for
things so we need to account for those in this job or an exception will
be thrown causing the job to fail.

app/services/discourse_subscriptions/campaign.rb

@@ -154,7 +154,8 @@ module DiscourseSubscriptions
           all_invoices =
             ::Stripe::Invoice.list(limit: 100, starting_after: current_set[:last_record])
 
-          current_set[:last_record] = all_invoices[:data].last[:id] if all_invoices[:data].present?
+          if all_invoices[:data].present?
+            current_set[:last_record] = all_invoices[:data].last[:id]
             current_set[:has_more] = all_invoices[:has_more]
 
             all_invoices[:data].each do |invoice|
@@ -162,7 +163,7 @@ module DiscourseSubscriptions
               next if invoice[:paid] != true
               line_item = invoice[:lines][:data][0] if invoice[:lines] && invoice[:lines][:data] # Discourse only makes single-line item charges
               # check if non-subscription and that the plan is active
-            if line_item[:plan] == nil && line_item[:price] &&
+              if line_item && line_item[:plan] == nil && line_item[:price] &&
                    line_item[:price][:recurring] == nil && line_item[:price][:active] == true
                 product_id = line_item[:price][:product]
                 if product_ids.include? product_id
@@ -175,6 +176,9 @@ module DiscourseSubscriptions
                 end
               end
             end
+          else
+            current_set[:has_more] = false
+          end
         end
       end
 

spec/services/campaign_spec.rb

@@ -62,6 +62,10 @@ describe DiscourseSubscriptions::Campaign do
         },
       }
     end
+    let(:invoice_with_nil_lines) { { id: "in_1236", paid: true, lines: nil } }
+    let(:invoice_with_nil_price) do
+      { id: "in_1237", paid: true, lines: { data: [{ plan: nil, price: nil }] } }
+    end
 
     before do
       Fabricate(:product, external_id: "prodct_23456")
@@ -104,6 +108,20 @@ describe DiscourseSubscriptions::Campaign do
           DiscourseSubscriptions::Campaign.new.refresh_data
           expect(Discourse.redis.get("subscriptions_goal_met_date")).to be_blank
         end
+
+        it "handles invoices with nil lines gracefully" do
+          ::Stripe::Subscription.expects(:list).returns(data: [subscription], has_more: false)
+          ::Stripe::Invoice.expects(:list).returns(data: [invoice_with_nil_lines], has_more: false)
+
+          expect { DiscourseSubscriptions::Campaign.new.refresh_data }.not_to raise_error
+        end
+
+        it "handles invoices with nil price gracefully" do
+          ::Stripe::Subscription.expects(:list).returns(data: [subscription], has_more: false)
+          ::Stripe::Invoice.expects(:list).returns(data: [invoice_with_nil_price], has_more: false)
+
+          expect { DiscourseSubscriptions::Campaign.new.refresh_data }.not_to raise_error
+        end
       end
 
       context "with a campaign product set" do