Add Redis strategy.

Gemfile

@@ -14,6 +14,7 @@ group :test do
   end
 
   gem "sqlite3", ">= 1.3", platform: :ruby
+  gem "fakeredis"
   gem "activerecord-jdbcsqlite3-adapter", platform: :jruby
   gem "minitest", ">= 4.2"
   gem "capybara", ">= 2.6"

README.md

@@ -82,6 +82,9 @@ The following strategies are provided:
     * `:httponly` – Whether the cookies are accessible via scripting or only HTTP. Default is `false`.
 * `:query_string` – Interpret query string parameters as features. This strategy is only used for resolving. It does not allow switching features on/off.
     * `:prefix` – String prefix for all query string parameters. Defaults to no prefix.
+* `:redis` – Save feature settings in Redis.
+    * `:client` – Use the specified Redis client instead of `Redis.new`.
+    * `:prefix` – String prefix for all Redis keys. Defaults to no prefix.
 * `:session` – Save feature settings in the current user's application session.
     * `:prefix` – String prefix for all session variables. Defaults to no prefix.
 * `:default` – Not strictly needed, all feature defaults will be applied if no strategies match a feature. Include this strategy to determine the order of using the default value, and to make it appear in the dashboard.

Rakefile

@@ -34,6 +34,6 @@ namespace :assets do
   end
 
   task :clean do
-    FileUtils.rm(stylesheet_path)
+    FileUtils.rm(stylesheet_path) rescue nil
   end
 end

lib/flipflop.rb

@@ -18,6 +18,7 @@
 require "flipflop/strategies/default_strategy"
 require "flipflop/strategies/lambda_strategy"
 require "flipflop/strategies/query_string_strategy"
+require "flipflop/strategies/redis_strategy"
 require "flipflop/strategies/session_strategy"
 require "flipflop/strategies/test_strategy"
 

lib/flipflop/strategies/active_record_strategy.rb

@@ -8,7 +8,7 @@ def default_description
       end
 
       def initialize(**options)
-        @class = options.delete(:class) || "Flipflop::Feature"
+        @class = options.delete(:class) || ::Flipflop::Feature
         if !@class.kind_of?(Class)
           @class = ActiveSupport::Inflector.constantize(@class.to_s)
         end

lib/flipflop/strategies/query_string_strategy.rb

@@ -15,7 +15,7 @@ def initialize(**options)
       def enabled?(feature)
         return unless request?
         return unless request.params.has_key?(param_key(feature))
-        request.params[param_key(feature)].to_s != "0"
+        request.params[param_key(feature)] != "0"
       end
 
       protected

lib/flipflop/strategies/redis_strategy.rb

@@ -0,0 +1,41 @@
+module Flipflop
+  module Strategies
+    class RedisStrategy < AbstractStrategy
+      class << self
+        def default_description
+          "Stores features in Redis. Applies to all users."
+        end
+      end
+
+      def initialize(**options)
+        @client = options.delete(:client) || ::Redis.new
+        @prefix = options.delete(:prefix).to_s.freeze
+        super(**options)
+      end
+
+      def switchable?
+        true
+      end
+
+      def enabled?(feature)
+        redis_value = @client.get(redis_key(feature))
+        return if redis_value.nil?
+        redis_value === "1"
+      end
+
+      def switch!(feature, enabled)
+        @client.set(redis_key(feature), enabled ? "1" : "0")
+      end
+
+      def clear!(feature)
+        @client.del(redis_key(feature))
+      end
+
+      protected
+
+      def redis_key(feature)
+        @prefix + feature.to_s
+      end
+    end
+  end
+end

lib/generators/flipflop/features/templates/features.rb

@@ -6,8 +6,9 @@
 
   # Other strategies:
   #
-  # strategy :session
   # strategy :query_string
+  # strategy :redis
+  # strategy :session
   #
   # strategy :my_strategy do |feature|
   #   # ... your custom code here; return true/false/nil.

test/unit/strategies/redis_strategy_test.rb

@@ -0,0 +1,97 @@
+require File.expand_path("../../../test_helper", __FILE__)
+
+require "fakeredis"
+
+describe Flipflop::Strategies::RedisStrategy do
+  before do
+    Redis.new.flushall
+  end
+
+  describe "with defaults" do
+    subject do
+      Flipflop::Strategies::RedisStrategy.new.freeze
+    end
+
+    it "should have default name" do
+      assert_equal "redis", subject.name
+    end
+
+    it "should have default description" do
+      assert_equal "Stores features in Redis. Applies to all users.",
+        subject.description
+    end
+
+    it "should be switchable" do
+      assert_equal true, subject.switchable?
+    end
+
+    it "should have unique key" do
+      assert_match /^\w+$/, subject.key
+    end
+
+    describe "with enabled feature" do
+      before do
+        Redis.new.set("one", 1)
+      end
+
+      it "should have feature enabled" do
+        assert_equal true, subject.enabled?(:one)
+      end
+
+      it "should be able to switch feature off" do
+        subject.switch!(:one, false)
+        assert_equal false, subject.enabled?(:one)
+      end
+
+      it "should be able to clear feature" do
+        subject.clear!(:one)
+        assert_nil subject.enabled?(:one)
+      end
+    end
+
+    describe "with disabled feature" do
+      before do
+        Redis.new.set("two", 0)
+      end
+
+      it "should not have feature enabled" do
+        assert_equal false, subject.enabled?(:two)
+      end
+
+      it "should be able to switch feature on" do
+        subject.switch!(:two, true)
+        assert_equal true, subject.enabled?(:two)
+      end
+
+      it "should be able to clear feature" do
+        subject.clear!(:two)
+        assert_nil subject.enabled?(:two)
+      end
+    end
+
+    describe "with unsaved feature" do
+      it "should not know feature" do
+        assert_nil subject.enabled?(:three)
+      end
+
+      it "should be able to switch feature on" do
+        subject.switch!(:three, true)
+        assert_equal true, subject.enabled?(:three)
+      end
+    end
+  end
+
+  describe "with options" do
+    subject do
+      Flipflop::Strategies::RedisStrategy.new(
+        client: Redis.new(db: 1),
+        prefix: "my_feature:",
+      ).freeze
+    end
+
+    it "should use prefix and database to resolve parameters" do
+      Redis.new(db: 1).set("my_feature:one", 1)
+      assert_equal true, subject.enabled?(:one)
+    end
+  end
+end