models: require belong_to associations on dossier

app/models/dossier.rb

@@ -75,10 +75,10 @@ class Dossier < ApplicationRecord
 
   has_many :dossier_operation_logs, -> { order(:created_at) }, dependent: :nullify, inverse_of: :dossier
 
-  belongs_to :groupe_instructeur
+  belongs_to :groupe_instructeur, optional: false
   has_one :procedure, through: :groupe_instructeur
   belongs_to :revision, class_name: 'ProcedureRevision', optional: true
-  belongs_to :user
+  belongs_to :user, optional: false
 
   accepts_nested_attributes_for :champs
   accepts_nested_attributes_for :champs_private

spec/factories/dossier.rb

@@ -2,7 +2,7 @@ FactoryBot.define do
   factory :dossier do
     autorisation_donnees { true }
     state { Dossier.states.fetch(:brouillon) }
-    association :user, factory: [:user]
+    association :user
 
     transient do
       procedure { nil }

spec/factories/etablissement.rb

@@ -25,9 +25,7 @@ FactoryBot.define do
     entreprise_date_creation { "1990-04-24" }
 
     trait :with_exercices do
-      after(:create) do |etablissement, _evaluator|
-        create(:exercice, etablissement: etablissement)
-      end
+      exercices { [association(:exercice)] }
     end
 
     trait :with_effectif_mensuel do

spec/factories/exercice.rb

@@ -3,6 +3,6 @@ FactoryBot.define do
     ca { '12345678' }
     date_fin_exercice { "2014-12-30 23:00:00" }
     date_fin_exercice_timestamp { 1419980400 }
-    association :etablissement, factory: [:etablissement]
+    association :etablissement
   end
 end