[#2258] Let dynamic type validate the type de champ

app/models/type_de_champ.rb

@@ -59,6 +59,17 @@ class TypeDeChamp < ApplicationRecord
   before_validation :check_mandatory
   before_save :remove_piece_justificative_template, if: -> { type_champ_changed? }
 
+  def valid?(context = nil)
+    super
+    if dynamic_type.present?
+      dynamic_type.valid?
+      errors.merge!(dynamic_type.errors)
+    end
+    errors.empty?
+  end
+
+  alias_method :validate, :valid?
+
   def set_dynamic_type
     @dynamic_type = type_champ.present? ? self.class.type_champ_to_class_name(type_champ).constantize.new(self) : nil
   end

app/models/types_de_champ/type_de_champ_base.rb

@@ -1,4 +1,6 @@
 class TypesDeChamp::TypeDeChampBase
+  include ActiveModel::Validations
+
   def initialize(type_de_champ)
     @type_de_champ = type_de_champ
   end

spec/models/type_de_champ_shared_example.rb

@@ -79,5 +79,26 @@ shared_examples 'type_de_champ_spec' do
         end
       end
     end
+
+    context 'delegate validation to dynamic type' do
+      subject { build(:type_de_champ_text) }
+      let(:dynamic_type) do
+        Class.new(TypesDeChamp::TypeDeChampBase) do
+          validate :never_valid
+
+          def never_valid
+            errors.add(:troll, 'always invalid')
+          end
+        end.new(subject)
+      end
+
+      before { subject.instance_variable_set(:@dynamic_type, dynamic_type) }
+
+      it { is_expected.to be_invalid }
+      it do
+        subject.validate
+        expect(subject.errors.full_messages.to_sentence).to eq('Troll always invalid')
+      end
+    end
   end
 end