valid period depend on trusted_device_token.created_at

app/controllers/users/sessions_controller.rb

@@ -75,8 +75,11 @@ class Users::SessionsController < Sessions::SessionsController
       .find_by(token: params[:jeton])
 
     if trusted_device_token&.token_valid?
-      trust_device
-      flash.notice = "Merci d’avoir confirmé votre connexion. Votre navigateur est maintenant authentifié pour #{TRUSTED_DEVICE_PERIOD.to_i / ActiveSupport::Duration::SECONDS_PER_DAY} jours."
+      trust_device(trusted_device_token.created_at)
+
+      period = ((trusted_device_token.created_at + TRUSTED_DEVICE_PERIOD) - Time.zone.now).to_i / ActiveSupport::Duration::SECONDS_PER_DAY
+
+      flash.notice = "Merci d’avoir confirmé votre connexion. Votre navigateur est maintenant authentifié pour #{period} jours."
 
       # redirect to procedure'url if stored by store_location_for(:user) in dossiers_controller
       # redirect to root_path otherwise

app/models/concerns/trusted_device_concern.rb

@@ -4,10 +4,10 @@ module TrustedDeviceConcern
   TRUSTED_DEVICE_COOKIE_NAME = :trusted_device
   TRUSTED_DEVICE_PERIOD = 1.month
 
-  def trust_device
+  def trust_device(start_at)
     cookies.encrypted[TRUSTED_DEVICE_COOKIE_NAME] = {
-      value: JSON.generate({ created_at: Time.zone.now }),
-      expires: TRUSTED_DEVICE_PERIOD,
+      value: JSON.generate({ created_at: start_at }),
+      expires: start_at + TRUSTED_DEVICE_PERIOD,
       httponly: true
     }
   end

spec/controllers/users/sessions_controller_spec.rb

@@ -239,9 +239,8 @@ describe Users::SessionsController, type: :controller do
 
     context 'when the cookie is outdated' do
       before do
-        Timecop.freeze(Time.zone.now - TrustedDeviceConcern::TRUSTED_DEVICE_PERIOD - 1.minute)
-        controller.trust_device(Time.zone.now)
-        Timecop.return
+        emission_date = Time.zone.now - TrustedDeviceConcern::TRUSTED_DEVICE_PERIOD - 1.minute
+        controller.trust_device(emission_date)
       end
 
       it { is_expected.to be false }