replaced order of redis connection creation

lib/sidekiq.rb

@@ -62,8 +62,8 @@ module Sidekiq
   end
 
   def self.redis(&block)
-    @redis ||= Sidekiq::RedisConnection.create
     raise ArgumentError, "requires a block" if !block
+    @redis ||= Sidekiq::RedisConnection.create
     @redis.with(&block)
   end
 

test/test_sidekiq.rb

@@ -11,4 +11,17 @@ class TestSidekiq < MiniTest::Unit::TestCase
     end
   end
 
+  describe "redis connection" do
+  	it "returns error without creating a connection if block is not given" do
+      mock = MiniTest::Mock.new
+      mock.expect :create, nil #Sidekiq::RedisConnection, create
+  		assert_raises(ArgumentError) {
+  			Sidekiq.redis
+  		}
+      assert_raises(MockExpectationError, "create should not be called") do
+        mock.verify
+      end
+  	end
+  end
+
 end