Schema graph_ql (#8406)

* First draft schema graph_ql

* Add tests for json schema procedures

spec/controllers/api/public/v1/json_description_procedures_controller_spec.rb

@@ -0,0 +1,37 @@
+RSpec.describe API::Public::V1::JSONDescriptionProceduresController, type: :controller do
+  include Rails.application.routes.url_helpers
+
+  describe '#show' do
+    let(:procedure) { create(:procedure, :published, :with_type_de_champ) }
+    subject(:show_request) do
+      get :show, params: params
+    end
+
+    before { show_request }
+
+    context 'the procedure is found' do
+      let(:params) { { path: procedure.path } }
+      let(:expected_response) do
+        API::V2::Schema.execute(API::V2::StoredQuery.get('ds-query-v2'),
+          variables: {
+            demarche: { "number": procedure.id },
+            includeRevision: true
+          },
+          operation_name: "getDemarcheDescriptor")
+          .to_h.dig("data", "demarcheDescriptor").to_json
+      end
+
+      it { expect(response).to have_http_status(:success) }
+
+      it { expect(response.body).to eq(expected_response) }
+    end
+
+    context "the procedure is not found" do
+      let(:params) { { path: "error" } }
+
+      it { expect(response).to have_http_status(:not_found) }
+
+      it { expect(response).to have_failed_with("procedure error is not found") }
+    end
+  end
+end