perf(dossier): memoize champ.sections on dossier

app/models/champ.rb

@@ -81,18 +81,8 @@ class Champ < ApplicationRecord
     !private?
   end
 
-  def siblings
-    if parent
-      parent&.champs
-    elsif public?
-      dossier&.champs
-    else
-      dossier&.champs_private
-    end
-  end
-
   def sections
-    siblings&.filter(&:header_section?)
+    @sections ||= dossier.sections_for(self)
   end
 
   def mandatory_and_blank?

app/models/dossier.rb

@@ -1122,6 +1122,20 @@ class Dossier < ApplicationRecord
     termine_expired_to_delete.find_each(&:purge_discarded)
   end
 
+  def sections_for(champ)
+    @sections = Hash.new do |hash, parent|
+      case parent
+      when :public
+        hash[parent] = champs.filter(&:header_section?)
+      when :private
+        hash[parent] = champs_private.filter(&:header_section?)
+      else
+        hash[parent] = parent.champs.filter(&:header_section?)
+      end
+    end
+    @sections[champ.parent || (champ.public? ? :public : :private)]
+  end
+
   private
 
   def create_missing_traitemets

spec/models/champ_spec.rb

@@ -69,19 +69,32 @@ describe Champ do
     end
   end
 
-  describe '#siblings' do
+  describe '#sections' do
-    let(:procedure) { create(:procedure, :with_type_de_champ, :with_type_de_champ_private, :with_repetition, types_de_champ_count: 1, types_de_champ_private_count: 1) }
+    let(:procedure) do
+      create(:procedure, :with_type_de_champ, :with_type_de_champ_private, :with_repetition, types_de_champ_count: 1, types_de_champ_private_count: 1).tap do |procedure|
+        create(:type_de_champ_header_section, procedure: procedure)
+        create(:type_de_champ_header_section, procedure: procedure, private: true)
+        create(:type_de_champ_header_section, parent: procedure.types_de_champ.find(&:repetition?))
+      end
+    end
     let(:dossier) { create(:dossier, procedure: procedure) }
     let(:public_champ) { dossier.champs.first }
     let(:private_champ) { dossier.champs_private.first }
     let(:champ_in_repetition) { dossier.champs.find(&:repetition?).champs.first }
-    let(:standalone_champ) { build(:champ, type_de_champ: build(:type_de_champ), dossier: nil) }
+    let(:standalone_champ) { build(:champ, type_de_champ: build(:type_de_champ), dossier: build(:dossier)) }
+    let(:public_sections) { dossier.champs.filter(&:header_section?) }
+    let(:private_sections) { dossier.champs_private.filter(&:header_section?) }
+    let(:sections_in_repetition) { champ_in_repetition.parent.champs.filter(&:header_section?) }
 
-    it 'returns the sibling champs of a champ' do
+    it 'returns the sibling sections of a champ' do
-      expect(public_champ.siblings).to eq(dossier.champs)
+      expect(public_sections).not_to be_empty
-      expect(private_champ.siblings).to eq(dossier.champs_private)
+      expect(private_sections).not_to be_empty
-      expect(champ_in_repetition.siblings).to eq(champ_in_repetition.parent.champs)
+      expect(sections_in_repetition).not_to be_empty
-      expect(standalone_champ.siblings).to be_nil
+
+      expect(public_champ.sections).to eq(public_sections)
+      expect(private_champ.sections).to eq(private_sections)
+      expect(champ_in_repetition.sections).to eq(sections_in_repetition)
+      expect(standalone_champ.sections).to eq([])
     end
   end