make the dossier prefillable

app/models/dossier.rb

@@ -43,6 +43,8 @@
 #  user_id                                            :integer
 #
 class Dossier < ApplicationRecord
+  include Dossier::Prefillable
+
   self.ignored_columns = [:en_construction_conservation_extension]
   include DossierFilteringConcern
   include DossierRebaseConcern

app/models/dossier/prefillable.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module Dossier::Prefillable
+  extend ActiveSupport::Concern
+
+  def prefill!(champs_public_attributes)
+    return unless champs_public_attributes.any?
+
+    assign_attributes(champs_public_attributes: champs_public_attributes)
+    save(validate: false)
+  end
+end

spec/models/dossier/prefillable_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+RSpec.describe Dossier::Prefillable do
+  describe '.prefill!' do
+    let(:procedure) { create(:procedure, :published) }
+    let(:dossier) { create(:dossier, :brouillon, procedure: procedure) }
+
+    subject(:fill) { dossier.prefill!(values) }
+
+    context 'when champs_public_attributes is empty' do
+      let(:values) { [] }
+
+      it "does nothing" do
+        expect(dossier).not_to receive(:save)
+        fill
+      end
+    end
+
+    context 'when champs_public_attributes has values' do
+      context 'when the champs are valid' do
+        let!(:type_de_champ_1) { create(:type_de_champ_text, procedure: procedure) }
+        let(:value_1) { "any value" }
+        let(:champ_id_1) { dossier.find_champ_by_stable_id(type_de_champ_1.stable_id).id }
+
+        let!(:type_de_champ_2) { create(:type_de_champ_phone, procedure: procedure) }
+        let(:value_2) { "33612345678" }
+        let(:champ_id_2) { dossier.find_champ_by_stable_id(type_de_champ_2.stable_id).id }
+
+        let(:values) { [{ id: champ_id_1, value: value_1 }, { id: champ_id_2, value: value_2 }] }
+
+        it "updates the champs with the new values" do
+          fill
+          expect(dossier.champs_public.first.value).to eq(value_1)
+          expect(dossier.champs_public.last.value).to eq(value_2)
+        end
+      end
+
+      context 'when a champ is invalid' do
+        let!(:type_de_champ) { create(:type_de_champ_phone, procedure: procedure) }
+        let(:value) { "a non phone value" }
+        let(:champ_id) { dossier.find_champ_by_stable_id(type_de_champ.stable_id).id }
+
+        let(:values) { [{ id: champ_id, value: value }] }
+
+        it "still updates the champ" do
+          expect { fill }.to change { dossier.champs_public.first.value }.from(nil).to(value)
+        end
+      end
+    end
+  end
+end