Reset weekly total shortfall when not applicable

app/models/case_log.rb

@@ -259,6 +259,11 @@ class CaseLog < ApplicationRecord
     hb == 7
   end
 
+  def receives_housing_related_benefits?
+    receives_housing_benefit_only? || receives_uc_with_housing_element_excl_housing_benefit? ||
+      receives_housing_benefit_and_universal_credit?
+  end
+
   def benefits_unknown?
     hb == 3
   end
@@ -351,10 +356,8 @@ private
       self.wtcharge = weekly_value(tcharge) if tcharge.present?
     end
     self.has_benefits = get_has_benefits
-    if tshortfall && (receives_housing_benefit_only? ||
+    self.wtshortfall = if tshortfall && receives_housing_related_benefits?
-        receives_housing_benefit_and_universal_credit? ||
+                         weekly_value(tshortfall)
-          receives_uc_with_housing_element_excl_housing_benefit?)
-      self.wtshortfall = weekly_value(tshortfall)
                        end
     self.nocharge = household_charge&.zero? ? 1 : 0
     self.underoccupation_benefitcap = 3 if renewal == 1 && year == 2021

spec/fixtures/exports/case_logs.xml

@@ -165,6 +165,6 @@
     <wpschrge>20.0</wpschrge>
     <wsupchrg>17.5</wsupchrg>
     <wtcharge>162.5</wtcharge>
-    <wtshortfall/>
+    <wtshortfall>6.0</wtshortfall>
   </form>
 </forms>

spec/models/case_log_spec.rb

@@ -299,6 +299,15 @@ RSpec.describe CaseLog do
           end
         end
 
+        context "when the tenant is not in receipt of applicable benefits" do
+          it "correctly resets total shortfall" do
+            case_log.update!(wtshortfall: 100, hb: 9)
+            record_from_db = ActiveRecord::Base.connection.execute("select wtshortfall from case_logs where id=#{case_log.id}").to_a[0]
+            expect(case_log.wtshortfall).to be_nil
+            expect(record_from_db["wtshortfall"]).to be_nil
+          end
+        end
+
         context "when rent is paid bi-weekly" do
           it "correctly derives and saves weekly rent" do
             case_log.update!(brent: 100, period: 0)