champ value return nil if champ is hidden

app/models/logic/champ_value.rb

@@ -22,14 +22,18 @@ class Logic::ChampValue < Logic::Term
   end
 
   def compute(champs)
+    targeted_champ = champ(champs)
+
+    return nil if !targeted_champ.visible?
+
     case type_de_champ.type_champ
     when MANAGED_TYPE_DE_CHAMP.fetch(:yes_no),
       MANAGED_TYPE_DE_CHAMP.fetch(:checkbox)
-      champ(champs).true?
+      targeted_champ.true?
     when MANAGED_TYPE_DE_CHAMP.fetch(:integer_number), MANAGED_TYPE_DE_CHAMP.fetch(:decimal_number)
-      champ(champs).for_api
+      targeted_champ.for_api
     when MANAGED_TYPE_DE_CHAMP.fetch(:drop_down_list)
-      champ(champs).value
+      targeted_champ.value
     end
   end
 

spec/models/logic/champ_value_spec.rb

@@ -18,6 +18,14 @@ describe Logic::ChampValue do
 
       it { is_expected.to be(false) }
     end
+
+    context 'with a value not visible' do
+      before do
+        expect(champ).to receive(:visible?).and_return(false)
+      end
+
+      it { is_expected.to be nil }
+    end
   end
 
   context 'integer tdc' do