LG-15273 Create a Redis Set to track Socure users

app/services/idv/socure_user.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Idv
+  class SocureUser
+    attr_reader :redis_pool
+
+    def initialize(redis_pool: REDIS_POOL)
+      @redis_pool = redis_pool
+    end
+
+    def add_user!(user_uuid:)
+      return if maxed_users?
+
+      redis_pool.with do |client|
+        client.sadd(key, user_uuid)
+      end
+    end
+
+    def count
+      redis_pool.with do |client|
+        client.scard(key)
+      end
+    end
+
+    private
+
+    def maxed_users?
+      count >= IdentityConfig.store.doc_auth_socure_max_allowed_users
+    end
+
+    def key
+      'idv:socure:users'
+    end
+  end
+end

spec/services/idv/socure_user_spec.rb

@@ -0,0 +1,58 @@
+require 'rails_helper'
+
+RSpec.describe Idv::SocureUser do
+  let(:socure_user_set) { Idv::SocureUser.new }
+  let(:dummy_uuid_1) { 'ABC0001' }
+  let(:dummy_uuid_2) { 'ABC0002' }
+  let(:dummy_uuid_3) { 'ABC0003' }
+
+  around do |ex|
+    REDIS_POOL.with { |client| client.flushdb }
+    ex.run
+    REDIS_POOL.with { |client| client.flushdb }
+  end
+
+  describe '#add_user!' do
+    before do
+      allow(IdentityConfig.store).to receive(:doc_auth_socure_max_allowed_users).and_return(2)
+    end
+
+    it 'correctly adds user and tracks count' do
+      socure_user_set.add_user!(user_uuid: dummy_uuid_1)
+      expect(socure_user_set.count).to eq(1)
+    end
+
+    it 'does not add duplicates' do
+      socure_user_set.add_user!(user_uuid: dummy_uuid_1)
+      expect(socure_user_set.count).to eq(1)
+      socure_user_set.add_user!(user_uuid: dummy_uuid_1)
+      expect(socure_user_set.count).to eq(1)
+    end
+
+    it 'does not allow more than doc_auth_socure_max_allowed_users to be added to set' do
+      socure_user_set.add_user!(user_uuid: dummy_uuid_1)
+      expect(socure_user_set.count).to eq(1)
+      socure_user_set.add_user!(user_uuid: dummy_uuid_2)
+      expect(socure_user_set.count).to eq(2)
+      socure_user_set.add_user!(user_uuid: dummy_uuid_3)
+      expect(socure_user_set.count).to eq(2)
+    end
+  end
+
+  describe '#count' do
+    before do
+      allow(IdentityConfig.store).to receive(:doc_auth_socure_max_allowed_users).and_return(10)
+    end
+    it 'count is zero when there are no users in the redis store' do
+      expect(socure_user_set.count).to eq(0)
+    end
+
+    it 'gives the user count' do
+      10.times.each do |index|
+        socure_user_set.add_user!(user_uuid: "ABC000#{index}")
+      end
+
+      expect(socure_user_set.count).to eq(10)
+    end
+  end
+end