[#1421] Handle mandatory fields

app/models/champs/linked_drop_down_list_champ.rb

@@ -32,6 +32,10 @@ class Champs::LinkedDropDownListChamp < Champ
     [primary_value, secondary_value].compact.join(' / ')
   end
 
+  def mandatory_and_blank?
+    mandatory? && (primary_value.blank? || secondary_value.blank?)
+  end
+
   private
 
   def value_for_export

spec/models/champs/linked_drop_down_list_champ_spec.rb

@@ -62,4 +62,40 @@ describe Champs::LinkedDropDownListChamp do
       it { is_expected.to eq('primary;secondary') }
     end
   end
+
+  describe '#mandatory_and_blank' do
+    let(:drop_down_list) { build(:drop_down_list, value: "--Primary--\nSecondary") }
+
+    subject { described_class.new(type_de_champ: type_de_champ) }
+
+    context 'when the champ is not mandatory' do
+      let(:type_de_champ) { build(:type_de_champ_linked_drop_down_list, drop_down_list: drop_down_list) }
+
+      it 'blank is fine' do
+        is_expected.not_to be_mandatory_and_blank
+      end
+    end
+
+    context 'when the champ is mandatory' do
+      let(:type_de_champ) { build(:type_de_champ_linked_drop_down_list, mandatory: true, drop_down_list: drop_down_list) }
+
+      context 'when there is no value' do
+        it { is_expected.to be_mandatory_and_blank }
+      end
+
+      context 'when there is a primary value' do
+        before { subject.primary_value = 'Primary' }
+
+        context 'when there is no secondary value' do
+          it { is_expected.to be_mandatory_and_blank }
+        end
+
+        context 'when there is a secondary value' do
+          before { subject.secondary_value = 'Primary' }
+
+          it { is_expected.not_to be_mandatory_and_blank }
+        end
+      end
+    end
+  end
 end