added support for redis connection pools

Gemfile

@@ -28,6 +28,7 @@ gem 'mysql2'
 gem 'pg'
 gem 'cuprite'
 gem 'puma'
+gem 'connection_pool'
 
 group(:guard) do
   gem 'guard'

lib/flipper/adapter.rb

@@ -1,8 +1,11 @@
+require 'flipper/adapters/poolable'
+
 module Flipper
   # Adding a module include so we have some hooks for stuff down the road
   module Adapter
     def self.included(base)
       base.extend(ClassMethods)
+      base.include(::Flipper::Adapters::Poolable)
     end
 
     module ClassMethods

lib/flipper/adapters/poolable.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Flipper
+  module Adapters
+    module Poolable
+      def initialize(client_or_pool = nil, key_prefix: nil)
+        @pool = nil
+        @client = nil
+        if client_or_pool.respond_to?(:with)
+          @pool = client_or_pool
+        else
+          @client = client_or_pool
+        end
+        @key_prefix = key_prefix
+      end
+
+      def self.included(klass)
+        klass.superclass.instance_methods(false).each do |method|
+          klass.define_method method do |*args|
+            return super(*args) unless @client.nil?
+
+            @pool.with do |client|
+              @client = client
+              super(*args)
+            ensure
+              @client = nil
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/flipper/adapters/redis_spec.rb

@@ -1,55 +1,7 @@
 require 'flipper/adapters/redis'
 
 RSpec.describe Flipper::Adapters::Redis do
-  let(:client) do
-    options = {}
+  subject { described_class.new(client, key_prefix: key_prefix) }
 
-    options[:url] = ENV['REDIS_URL'] if ENV['REDIS_URL']
-
-    Redis.raise_deprecations = true
-    Redis.new(options)
-  end
-
-  subject { described_class.new(client) }
-
-  before do
-    skip_on_error(Redis::CannotConnectError, 'Redis not available') do
-      client.flushdb
-    end
-  end
-
-  it_should_behave_like 'a flipper adapter'
-
-  it 'configures itself on load' do
-    Flipper.configuration = nil
-    Flipper.instance = nil
-
-    silence { load 'flipper/adapters/redis.rb' }
-
-    expect(Flipper.adapter.adapter).to be_a(Flipper::Adapters::Redis)
-  end
-
-  describe 'with a key_prefix' do
-    let(:subject) { described_class.new(client, key_prefix: "lockbox:") }
-    let(:feature) { Flipper::Feature.new(:search, subject) }
-
-    it_should_behave_like 'a flipper adapter'
-
-    it 'namespaces feature-keys' do
-      subject.add(feature)
-
-      expect(client.smembers("flipper_features")).to eq([])
-      expect(client.exists?("search")).to eq(false)
-      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
-      expect(client.hgetall("lockbox:search")).not_to eq(nil)
-    end
-
-    it "can remove namespaced keys" do
-      subject.add(feature)
-      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
-
-      subject.remove(feature)
-      expect(client.smembers("lockbox:flipper_features")).to be_empty
-    end
-  end
+  it_behaves_like "a redis adapter"
 end

spec/support/examples/redis_adapter.rb

@@ -0,0 +1,55 @@
+RSpec.shared_examples "a redis adapter" do
+  let(:create_client) do
+    Proc.new do
+      options = {}
+
+      options[:url] = ENV['REDIS_URL'] if ENV['REDIS_URL']
+
+      Redis.raise_deprecations = true
+      Redis.new(options)
+    end
+  end
+  let(:client) { create_client.call }
+  let(:key_prefix) { nil }
+
+  before do
+    skip_on_error(Redis::CannotConnectError, 'Redis not available') do
+      client.flushdb
+    end
+  end
+
+  it_should_behave_like 'a flipper adapter'
+
+  it 'configures itself on load' do
+    Flipper.configuration = nil
+    Flipper.instance = nil
+
+    silence { load 'flipper/adapters/redis.rb' }
+
+    expect(Flipper.adapter.adapter).to be_a(described_class)
+  end
+
+  describe 'with a key_prefix' do
+    let(:feature) { Flipper::Feature.new(:search, subject) }
+    let(:key_prefix) { "lockbox:" }
+
+    it_should_behave_like 'a flipper adapter'
+
+    it 'namespaces feature-keys' do
+      subject.add(feature)
+
+      expect(client.smembers("flipper_features")).to eq([])
+      expect(client.exists?("search")).to eq(false)
+      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
+      expect(client.hgetall("lockbox:search")).not_to eq(nil)
+    end
+
+    it "can remove namespaced keys" do
+      subject.add(feature)
+      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
+
+      subject.remove(feature)
+      expect(client.smembers("lockbox:flipper_features")).to be_empty
+    end
+  end
+end