Sign in with a user linked by france connect sub (openid)

instead of looking linked user by email because :

- follows FC recommendation to fetch ds account by openid
- the email is not a valid key as many user can share the same FCI email.

The following scenario is now working

A user A (email: 1@mail.com) uses FC to connect to DS
=> It is connected as 1@mail.com

Another user B (email: generic@mail.com) uses FC to connect
=> It is connected as generic@mail.com

The first user A change its FC email to generic@mail.com and connect to DS
=> It is still connected as 1@mail.com

app/controllers/france_connect/particulier_controller.rb

@@ -11,7 +11,10 @@ class FranceConnect::ParticulierController < ApplicationController
 
   def callback
     fci = FranceConnectService.find_or_retrieve_france_connect_information(params[:code])
+
+    if fci.user.nil?
       fci.associate_user!
+    end
 
     user = fci.user
 

app/models/france_connect_information.rb

@@ -21,9 +21,6 @@ class FranceConnectInformation < ApplicationRecord
   validates :france_connect_particulier_id, presence: true, allow_blank: false, allow_nil: false
 
   def associate_user!
-    user = User.find_by(email: email_france_connect.downcase)
-
-    if user.nil?
     begin
       user = User.create!(
         email: email_france_connect.downcase,
@@ -36,7 +33,6 @@ class FranceConnectInformation < ApplicationRecord
       # At the 2nd call, user is nil but exception is raised at the creation of the user
       # because the first call has already created a user
     end
-    end
 
     update_attribute('user_id', user.id)
     touch # needed to update updated_at column

spec/controllers/france_connect/particulier_controller_spec.rb

@@ -1,6 +1,6 @@
 describe FranceConnect::ParticulierController, type: :controller do
   let(:birthdate) { '20150821' }
-  let(:email) { 'test@test.com' }
+  let(:email) { 'email_from_fc@test.com' }
 
   let(:user_info) do
     {
@@ -49,15 +49,18 @@ describe FranceConnect::ParticulierController, type: :controller do
           .and_return(FranceConnectInformation.new(user_info))
       end
 
-      context 'when france_connect_particulier_id exist in database' do
-        let!(:france_connect_information) { create(:france_connect_information, :with_user, user_info) }
-        let(:user) { france_connect_information.user }
+      context 'when france_connect_particulier_id exists in database' do
+        let!(:fci) { FranceConnectInformation.create!(user_info.merge(user_id: fc_user.id)) }
+
+        context 'and is linked to an user' do
+          let(:fc_user) { create(:user, email: 'associated_user@a.com') }
 
           it { expect { subject }.not_to change { FranceConnectInformation.count } }
 
-        it do
+          it 'signs in with the fci associated user' do
             subject
-          expect(user.reload.loged_in_with_france_connect).to eq(User.loged_in_with_france_connects.fetch(:particulier))
+            expect(controller.current_user).to eq(fc_user)
+            expect(fc_user.reload.loged_in_with_france_connect).to eq(User.loged_in_with_france_connects.fetch(:particulier))
           end
 
           context 'and the user has a stored location' do
@@ -66,14 +69,17 @@ describe FranceConnect::ParticulierController, type: :controller do
 
             it { is_expected.to redirect_to(stored_location) }
           end
+        end
+
+        context 'and is linked an instructeur' do
+          let(:fc_user) { create(:instructeur, email: 'another_email@a.com').user }
 
-        context 'and the user is also instructeur' do
-          let!(:instructeur) { create(:instructeur, email: email) }
           before { subject }
 
-          it { expect(response).to redirect_to(new_user_session_path) }
-
-          it { expect(flash[:alert]).to be_present }
+          it do
+            expect(response).to redirect_to(new_user_session_path)
+            expect(flash[:alert]).to be_present
+          end
         end
       end
 

spec/models/france_connect_information_spec.rb

@@ -18,15 +18,5 @@ describe FranceConnectInformation, type: :model do
         expect(fci.user.email).to eq(fci.email_france_connect)
       end
     end
-
-    context 'when a user with same email (but who is not an instructeur) exist' do
-      let(:user) { create(:user) }
-      let(:fci) { build(:france_connect_information, email_france_connect: user.email) }
-      let(:subject) { fci.associate_user! }
-
-      before { subject }
-
-      it { expect(fci.user).to eq(user) }
-    end
   end
 end