models: fix touch not propagating when using nested attributes

Sometimes, when using nested attributes, touch doesn’t propagate to
parent relationships. (see https://github.com/rails/rails/issues/26726)

Specifically, this happens in our app when updating a dossier with
only new attachements (but without changing the value of any fields).

To work around this, we need to define the parent relationship
explicitely. This is good practice anyway.

Fix #3906

app/models/avis.rb

@@ -1,7 +1,7 @@
 class Avis < ApplicationRecord
   include EmailSanitizableConcern
 
-  belongs_to :dossier, touch: true
+  belongs_to :dossier, inverse_of: :avis, touch: true
   belongs_to :gestionnaire
   belongs_to :claimant, class_name: 'Gestionnaire'
 

app/models/champ.rb

@@ -1,5 +1,5 @@
 class Champ < ApplicationRecord
-  belongs_to :dossier, touch: true
+  belongs_to :dossier, inverse_of: :champs, touch: true
   belongs_to :type_de_champ, inverse_of: :champ
   belongs_to :parent, class_name: 'Champ'
   has_many :commentaires

app/models/commentaire.rb

@@ -1,5 +1,5 @@
 class Commentaire < ApplicationRecord
-  belongs_to :dossier, touch: true
+  belongs_to :dossier, inverse_of: :commentaires, touch: true
   belongs_to :piece_justificative
 
   belongs_to :user

app/models/dossier.rb

@@ -19,18 +19,18 @@ class Dossier < ApplicationRecord
   has_one :individual, dependent: :destroy
   has_one :attestation, dependent: :destroy
 
-  has_many :pieces_justificatives, dependent: :destroy
+  has_many :pieces_justificatives, inverse_of: :dossier, dependent: :destroy
   has_one_attached :justificatif_motivation
 
-  has_many :champs, -> { root.public_only.ordered }, dependent: :destroy
-  has_many :champs_private, -> { root.private_only.ordered }, class_name: 'Champ', dependent: :destroy
-  has_many :commentaires, dependent: :destroy
+  has_many :champs, -> { root.public_only.ordered }, inverse_of: :dossier, dependent: :destroy
+  has_many :champs_private, -> { root.private_only.ordered }, class_name: 'Champ', inverse_of: :dossier, dependent: :destroy
+  has_many :commentaires, inverse_of: :dossier, dependent: :destroy
   has_many :invites, dependent: :destroy
   has_many :follows, -> { active }
   has_many :previous_follows, -> { inactive }, class_name: 'Follow'
   has_many :followers_gestionnaires, through: :follows, source: :gestionnaire
   has_many :previous_followers_gestionnaires, -> { distinct }, through: :previous_follows, source: :gestionnaire
-  has_many :avis, dependent: :destroy
+  has_many :avis, inverse_of: :dossier, dependent: :destroy
 
   has_many :dossier_operation_logs, dependent: :destroy
 

app/models/piece_justificative.rb

@@ -1,5 +1,5 @@
 class PieceJustificative < ApplicationRecord
-  belongs_to :dossier, touch: true
+  belongs_to :dossier, inverse_of: :pieces_justificatives, touch: true
   belongs_to :type_de_piece_justificative
   has_one :commentaire
 

spec/controllers/users/dossiers_controller_spec.rb

@@ -386,9 +386,11 @@ describe Users::DossiersController, type: :controller do
 
   describe '#update_brouillon' do
     before { sign_in(user) }
+
     let!(:dossier) { create(:dossier, user: user) }
     let(:first_champ) { dossier.champs.first }
     let(:value) { 'beautiful value' }
+    let(:now) { Time.zone.parse('01/01/2100') }
     let(:submit_payload) do
       {
         id: dossier.id,
@@ -402,7 +404,11 @@ describe Users::DossiersController, type: :controller do
     end
     let(:payload) { submit_payload }
 
-    subject { patch :update_brouillon, params: payload }
+    subject do
+      Timecop.freeze(now) do
+        patch :update_brouillon, params: payload
+      end
+    end
 
     context 'when the dossier cannot be updated by the user' do
       let!(:dossier) { create(:dossier, :en_instruction, user: user) }
@@ -421,6 +427,7 @@ describe Users::DossiersController, type: :controller do
 
         expect(response).to redirect_to(merci_dossier_path(dossier))
         expect(first_champ.reload.value).to eq('beautiful value')
+        expect(dossier.reload.updated_at.year).to eq(2100)
         expect(dossier.reload.state).to eq(Dossier.states.fetch(:en_construction))
       end
 
@@ -549,9 +556,15 @@ describe Users::DossiersController, type: :controller do
 
   describe '#update' do
     before { sign_in(user) }
-    let!(:dossier) { create(:dossier, :en_construction, user: user) }
+
+    let(:procedure) { create(:procedure, :published, :with_type_de_champ, :with_piece_justificative) }
+    let!(:dossier) { create(:dossier, :en_construction, user: user, procedure: procedure) }
     let(:first_champ) { dossier.champs.first }
+    let(:piece_justificative_champ) { dossier.champs.last }
     let(:value) { 'beautiful value' }
+    let(:file) { Rack::Test::UploadedFile.new("./spec/fixtures/files/piece_justificative_0.pdf", 'application/pdf') }
+    let(:now) { Time.zone.parse('01/01/2100') }
+
     let(:submit_payload) do
       {
         id: dossier.id,
@@ -565,7 +578,11 @@ describe Users::DossiersController, type: :controller do
     end
     let(:payload) { submit_payload }
 
-    subject { patch :update, params: payload }
+    subject do
+      Timecop.freeze(now) do
+        patch :update, params: payload
+      end
+    end
 
     context 'when the dossier cannot be updated by the user' do
       let!(:dossier) { create(:dossier, :en_instruction, user: user) }
@@ -584,8 +601,28 @@ describe Users::DossiersController, type: :controller do
 
         expect(response).to redirect_to(demande_dossier_path(dossier))
         expect(first_champ.reload.value).to eq('beautiful value')
+        expect(dossier.reload.updated_at.year).to eq(2100)
         expect(dossier.reload.state).to eq(Dossier.states.fetch(:en_construction))
       end
+
+      context 'when only files champs are modified' do
+        let(:submit_payload) do
+          {
+            id: dossier.id,
+            dossier: {
+              champs_attributes: {
+                id: piece_justificative_champ.id,
+                piece_justificative_file: file
+              }
+            }
+          }
+        end
+
+        it 'updates the dossier modification date' do
+          subject
+          expect(dossier.reload.updated_at.year).to eq(2100)
+        end
+      end
     end
 
     context 'when the update fails' do

spec/factories/procedure.rb

@@ -127,6 +127,14 @@ FactoryBot.define do
       end
     end
 
+    trait :with_piece_justificative do
+      after(:build) do |procedure, _evaluator|
+        type_de_champ = create(:type_de_champ_piece_justificative)
+        procedure.types_de_champ << type_de_champ
+      end
+    end
+
+    # Deprecated
     trait :with_two_type_de_piece_justificative do
       after(:build) do |procedure, _evaluator|
         rib = create(:type_de_piece_justificative, :rib, order_place: 1)