add prefill decorator for multiple drop down list

app/models/types_de_champ/prefill_multiple_drop_down_list_type_de_champ.rb

@@ -0,0 +1,8 @@
+class TypesDeChamp::PrefillMultipleDropDownListTypeDeChamp < TypesDeChamp::PrefillDropDownListTypeDeChamp
+  def example_value
+    return nil if possible_values.empty?
+    return possible_values.first if possible_values.one?
+
+    [possible_values.first, possible_values.second]
+  end
+end

app/models/types_de_champ/prefill_type_de_champ.rb

@@ -5,6 +5,8 @@ class TypesDeChamp::PrefillTypeDeChamp < SimpleDelegator
     case type_de_champ.type_champ
     when TypeDeChamp.type_champs.fetch(:drop_down_list)
       TypesDeChamp::PrefillDropDownListTypeDeChamp.new(type_de_champ)
+    when TypeDeChamp.type_champs.fetch(:multiple_drop_down_list)
+      TypesDeChamp::PrefillMultipleDropDownListTypeDeChamp.new(type_de_champ)
     when TypeDeChamp.type_champs.fetch(:pays)
       TypesDeChamp::PrefillPaysTypeDeChamp.new(type_de_champ)
     when TypeDeChamp.type_champs.fetch(:regions)

spec/models/types_de_champ/prefill_multiple_drop_down_list_type_de_champ_spec.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+RSpec.describe TypesDeChamp::PrefillMultipleDropDownListTypeDeChamp do
+  describe 'ancestors' do
+    subject { described_class.new(build(:type_de_champ_multiple_drop_down_list)) }
+
+    it { is_expected.to be_kind_of(TypesDeChamp::PrefillDropDownListTypeDeChamp) }
+  end
+
+  describe '#example_value' do
+    let(:type_de_champ) { build(:type_de_champ_multiple_drop_down_list, drop_down_list_value: drop_down_list_value) }
+    subject(:example_value) { described_class.new(type_de_champ).example_value }
+
+    context 'when the multiple drop down list has no option' do
+      let(:drop_down_list_value) { "" }
+
+      it { expect(example_value).to eq(nil) }
+    end
+
+    context 'when the multiple drop down list only has one option' do
+      let(:drop_down_list_value) { "value" }
+
+      it { expect(example_value).to eq("value") }
+    end
+
+    context 'when the multiple drop down list has two options or more' do
+      let(:drop_down_list_value) {  "value1\r\nvalue2\r\nvalue3" }
+
+      it { expect(example_value).to eq(["value1", "value2"]) }
+    end
+  end
+end

spec/models/types_de_champ/prefill_type_de_champ_spec.rb

@@ -10,6 +10,12 @@ RSpec.describe TypesDeChamp::PrefillTypeDeChamp, type: :model do
       it { expect(built).to be_kind_of(TypesDeChamp::PrefillDropDownListTypeDeChamp) }
     end
 
+    context 'when the type de champ is a multiple_drop_down_list' do
+      let(:type_de_champ) { build(:type_de_champ_multiple_drop_down_list) }
+
+      it { expect(built).to be_kind_of(TypesDeChamp::PrefillMultipleDropDownListTypeDeChamp) }
+    end
+
     context 'when the type de champ is a pays' do
       let(:type_de_champ) { build(:type_de_champ_pays) }