Add SIRET champs support to the API

app/serializers/champs/siret_champ_serializer.rb

@@ -0,0 +1,12 @@
+class Champs::SiretChampSerializer < ChampSerializer
+  has_one :etablissement
+  has_one :entreprise
+
+  def etablissement
+    object.etablissement
+  end
+
+  def entreprise
+    object.etablissement&.entreprise
+  end
+end

spec/serializers/champs/siret_champ_serializer_spec.rb

@@ -0,0 +1,16 @@
+describe Champs::SiretChampSerializer do
+  describe '#attributes' do
+    subject { Champs::SiretChampSerializer.new(champ).serializable_hash }
+
+    context 'when type champ is siret' do
+      let(:etablissement) { create(:etablissement) }
+      let(:champ) { create(:type_de_champ_siret).champ.create(etablissement: etablissement, value: etablissement.siret) }
+
+      it {
+        is_expected.to include(value: etablissement.siret)
+        expect(subject[:etablissement]).to include(siret: etablissement.siret)
+        expect(subject[:entreprise]).to include(capital_social: etablissement.entreprise_capital_social)
+      }
+    end
+  end
+end