Allow host app to configure Redis client options

Author: yarmiganosca

lib/kracken/config.rb

@@ -3,7 +3,7 @@
 module Kracken
   class Config
     attr_accessor :app_id, :app_secret
-    attr_writer :provider_url
+    attr_writer :provider_url, :redis_options
 
     # @deprecated the associated reader returns static `::User`
     attr_writer :user_class
@@ -16,6 +16,10 @@ def provider_url
       @provider_url ||= PROVIDER_URL
     end
 
+    def redis_options
+      @redis_options ||= {}
+    end
+
     def user_class
       ::User
     end

lib/kracken/session_manager.rb

@@ -1,13 +1,27 @@
 # frozen_string_literal: true
 
+require 'redis'
+
 module Kracken
   module SessionManager
     def self.conn
-      @conn ||= if ENV["REDIS_SESSION_URL"].present?
-                  Redis.new(url: ENV["REDIS_SESSION_URL"])
-                else
-                  NullRedis.new
-                end
+      @conn ||=
+        begin
+          default_redis_options = { url: ENV['REDIS_SESSION_URL'] }
+          redis_options = default_redis_options.merge(Kracken.config.redis_options).compact
+
+          if redis_options.any?
+            Redis.new(**redis_options)
+          else
+            NullRedis.new
+          end
+        end
+    end
+
+    # @api private
+    # For use in testing only
+    def self.reset_conn
+      @conn = nil
     end
 
     def self.get(user_id)

spec/kracken/config_spec.rb

@@ -5,7 +5,7 @@
 module Kracken
   RSpec.describe Config do
 
-    subject(:config){ Kracken::Config.new }
+    subject(:config) { Kracken::Config.new }
 
     it "sets a default url" do
       expect(config.provider_url).to eq "https://account.radiusnetworks.com"
@@ -22,5 +22,18 @@ module Kracken
       expect(config.provider_url).to eq "http://joe.com"
     end
 
+    describe "#redis_options" do
+      it 'defaults to {}' do
+        expect(config.redis_options).to eq({})
+      end
+    end
+
+    describe "#redis_options=" do
+      it 'allows redis_options to be set' do
+        config.redis_options = { url: "redis://www.example.com" }
+
+        expect(config.redis_options).to eq({ url: "redis://www.example.com" })
+      end
+    end
   end
 end

spec/kracken/session_manager_spec.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+module Kracken
+  RSpec.describe SessionManager do
+    include Kracken::Spec::UsingEnv
+
+    describe "::conn" do
+      before { SessionManager.reset_conn }
+
+      context "when the REDIS_SESSION_URL env var is present" do
+        it 'is a Redis instance' do
+          using_env({ "REDIS_SESSION_URL" => "redis://www.example.com" }) do
+            expect(SessionManager.conn).to be_an_instance_of Redis
+          end
+        end
+      end
+
+      context "when the REDIS_SESSION_URL env var is not present" do
+        it 'is a NullRedis instance' do
+          expect(SessionManager.conn).to be_an_instance_of SessionManager::NullRedis
+        end
+      end
+    end
+  end
+end

spec/support/using_env.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Kracken
+  module Spec
+    module UsingEnv
+      # By forcing the use of a block, this makes working within the context of
+      # a single spec much easier. If this needs to be wrapped around multiple
+      # specs, then an appropriate #around(:example) hook may be used.
+      #
+      # This is stolen with love from https://github.com/RadiusNetworks/captain/blob/master/spec/support/using_env.rb
+      #
+      # @param env_stubs [Hash{String => Object}]
+      #
+      # @yieldreturn
+      def using_env(env_stubs) # rubocop:disable Metrics/MethodLength
+        keys_to_delete = env_stubs.keys - ENV.keys
+        original_values = env_stubs.each_with_object({}) { |(k, v), env|
+          env[k] = ENV[k] if ENV.key?(k)
+          ENV[k] = v
+        }
+        yield
+      ensure
+        keys_to_delete.each do |k|
+          ENV.delete(k)
+        end
+        original_values.each do |k, v|
+          ENV[k] = v
+        end
+      end
+    end
+  end
+end