CLDC-3850: Clear postcode known when clearing postcode full (#2912)

* CLDC-3850: Clear postcode known when clearing postcode full

* Reword test names for linting

app/models/log.rb

@@ -248,6 +248,11 @@ class Log < ApplicationRecord
   end
 
   def blank_compound_invalid_non_setup_fields!
+    if errors.attribute_names.include? :postcode_full
+      self.postcode_known = nil if lettings?
+      self.pcodenk = nil if sales?
+    end
+
     self.ppcodenk = nil if errors.attribute_names.include? :ppostcode_full
     self.previous_la_known = nil if errors.attribute_names.include? :prevloc
 
@@ -258,6 +263,8 @@ class Log < ApplicationRecord
       self.address_line2 = nil
       self.town_or_city = nil
       self.postcode_full = nil
+      self.postcode_known = nil if lettings?
+      self.pcodenk = nil if sales?
       self.county = nil
       process_postcode_changes!
     end

spec/models/log_spec.rb

@@ -101,5 +101,29 @@ RSpec.describe Log, type: :model do
         expect(model.joint).to be_nil
       end
     end
+
+    context "when postcode_full is invalid" do
+      context "with a lettings log" do
+        subject(:model) { build_stubbed(:lettings_log, :setup_completed, postcode_full: "not a postcode", postcode_known: 1) }
+
+        it "blanks it and postcode_known" do
+          model.valid?
+          model.blank_invalid_non_setup_fields!
+          expect(model.postcode_full).to be_nil
+          expect(model.postcode_known).to be_nil
+        end
+      end
+
+      context "with a sales log" do
+        subject(:model) { build_stubbed(:sales_log, :discounted_ownership_setup_complete, postcode_full: "not a postcode", pcodenk: 0) }
+
+        it "blanks it and pcodenk" do
+          model.valid?
+          model.blank_invalid_non_setup_fields!
+          expect(model.postcode_full).to be_nil
+          expect(model.pcodenk).to be_nil
+        end
+      end
+    end
   end
 end