[Fix #285] Use a has_many through for Gestionnaire#dossiers_follow

app/models/gestionnaire.rb

@@ -9,6 +9,7 @@ class Gestionnaire < ActiveRecord::Base
   has_many :assign_to, dependent: :destroy
   has_many :procedures, through: :assign_to
   has_many :dossiers, -> { where.not(state: :draft) }, through: :procedures
+  has_many :dossiers_follow, through: :follows, source: :dossier
   has_many :follows
   has_many :preference_list_dossiers
 
@@ -17,10 +18,6 @@ class Gestionnaire < ActiveRecord::Base
 
   include CredentialsSyncableConcern
 
-  def dossiers_follow
-    @dossiers_follow ||= dossiers.joins(:follows).where("follows.gestionnaire_id = #{id}")
-  end
-
   def procedure_filter
     return nil unless assign_to.pluck(:procedure_id).include?(self[:procedure_filter])
 

spec/models/gestionnaire_spec.rb

@@ -116,19 +116,6 @@ describe Gestionnaire, type: :model do
     end
   end
 
-  describe '#dossiers_follow' do
-    let!(:dossier) { create :dossier, procedure: procedure, state: :initiated }
-
-    before do
-      create :follow, dossier_id: dossier.id, gestionnaire_id: gestionnaire.id
-    end
-
-    subject { gestionnaire.dossiers_follow }
-
-    it { expect(Follow.all.size).to eq 1 }
-    it { expect(subject.first).to eq dossier }
-  end
-
   describe '#build_default_preferences_list_dossier' do
     subject { gestionnaire.preference_list_dossiers }