add more generic error handling

modules/travel_pay/app/services/travel_pay/claims_service.rb

@@ -50,9 +50,15 @@ def get_claims_by_date_range(params = {}) # rubocop:disable Metrics/MethodLength
                               'message' => e.message,
                               'success' => false
                             }, status: 400)
-    rescue => e
+    rescue Common::Exceptions::BackendServiceException => e
       Rails.logger.error(message: "#{e}, #{e.original_body}")
       Faraday::Response.new(response_body: e.original_body, status: e.original_status)
+    rescue => e
+      Faraday::Response.new(response_body: {
+                              'statusCode' => 520, # Unknown error code
+                              'message' => "An unknown error occored: #{e}",
+                              'success' => false
+                            }, status: 520)
     end
 
     def get_claim_by_id(claim_id)

modules/travel_pay/spec/services/claims_service_spec.rb

@@ -271,6 +271,20 @@
       expect(bad_claims_call.body['message']).to include(/Both start and end/i)
     end
 
+    it 'handles random, unknown errors' do
+      allow_any_instance_of(TravelPay::ClaimsClient)
+        .to receive(:get_claims_by_date)
+        .and_raise(NameError.new('Uninitialized constant.', 'new_constant'))
+
+      bad_claims_call = @service.get_claims_by_date_range(
+        { 'start_date' => '2024-01-01T16:45:34Z', 'end_date' => '2024-01-01T16:45:34Z' }
+      )
+      expect(bad_claims_call.status).to equal(520)
+      expect(bad_claims_call.body['statusCode']).to equal(520)
+      expect(bad_claims_call.body['success']).to eq(false)
+      expect(bad_claims_call.body['message']).to include(/Uninitialized constant/i)
+    end
+
     it 'returns 400 with error message if dates are invalid' do
       allow_any_instance_of(TravelPay::ClaimsClient)
         .to receive(:get_claims_by_date)