Controller spec to confirm writing of cookie

app/controllers/email_confirmation_controller.rb

@@ -2,11 +2,14 @@
 class EmailConfirmationController < ApplicationController
   def verify
     @member = Member.find_by(email: params[:email])
+
     errors = EmailVerifierService.verify(params[:token], params[:email], cookies)
+
     @rendered = template.render(
       'errors' => errors,
       'members_dashboard_url' => Settings.members.dashboard_url
     ).html_safe
+
     render 'email_confirmation/follow_up', layout: 'generic'
   end
 

spec/controllers/email_confirmation_spec.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+describe EmailConfirmationController do
+  describe 'verify' do
+    include AuthToken
+
+    let(:member) { create(:member) }
+    let(:authentication) { create(:member_authentication, member: member) }
+
+    it 'sets cookie' do
+      post :verify, token: authentication.token, email: member.email
+
+      payload = decode_jwt(cookies.signed['authentication_id'])
+      expect(payload['email']).to eq(member.email)
+    end
+  end
+end