Remove usage of assigns in controller specs (#30195)

spec/controllers/settings/two_factor_authentication/confirmations_controller_spec.rb

@@ -9,11 +9,16 @@ describe Settings::TwoFactorAuthentication::ConfirmationsController do
     it 'renders the new view' do
       subject
 
-      expect(assigns(:confirmation)).to be_instance_of Form::TwoFactorConfirmation
-      expect(assigns(:provision_url)).to eq 'otpauth://totp/cb6e6126.ngrok.io:local-part%40domain?secret=thisisasecretforthespecofnewview&issuer=cb6e6126.ngrok.io'
-      expect(assigns(:qrcode)).to be_instance_of RQRCode::QRCode
       expect(response).to have_http_status(200)
       expect(response).to render_template(:new)
+      expect(response.body)
+        .to include(qr_code_markup)
+    end
+
+    def qr_code_markup
+      RQRCode::QRCode.new(
+        'otpauth://totp/cb6e6126.ngrok.io:local-part%40domain?secret=thisisasecretforthespecofnewview&issuer=cb6e6126.ngrok.io'
+      ).as_svg(padding: 0, module_size: 4)
     end
   end
 
@@ -61,10 +66,10 @@ describe Settings::TwoFactorAuthentication::ConfirmationsController do
             expect { post_create_with_options }
               .to change { user.reload.otp_secret }.to 'thisisasecretforthespecofnewview'
 
-            expect(assigns(:recovery_codes)).to eq otp_backup_codes
             expect(flash[:notice]).to eq 'Two-factor authentication successfully enabled'
             expect(response).to have_http_status(200)
             expect(response).to render_template('settings/two_factor_authentication/recovery_codes/index')
+            expect(response.body).to include(*otp_backup_codes)
           end
         end
 

spec/controllers/settings/two_factor_authentication/recovery_codes_controller_spec.rb

@@ -15,10 +15,11 @@ describe Settings::TwoFactorAuthentication::RecoveryCodesController do
       sign_in user, scope: :user
       post :create, session: { challenge_passed_at: Time.now.utc }
 
-      expect(assigns(:recovery_codes)).to eq otp_backup_codes
       expect(flash[:notice]).to eq 'Recovery codes successfully regenerated'
       expect(response).to have_http_status(200)
       expect(response).to render_template(:index)
+      expect(response.body)
+        .to include(*otp_backup_codes)
     end
 
     it 'redirects when not signed in' do