FIX: Add Redis 5 support

Redis 5 is picky about the params you send it, in 4 and below you could ship
it arbitrary params and it would simply ignore. In 5 it requires specific ones.


The change also removes a non relevant test case, Redis::Client::Connector
is no longer a thing Redis gem version 5 and up.

Redis 5 gem also duplicates incoming params so it is inherently more safe.

CHANGELOG

@@ -1,3 +1,7 @@
+FUTURE
+
+  - FIX: Add redis version 5 support
+
 22-02-2022
 
 - Version 4.2.0

lib/message_bus/backends/redis.rb

@@ -346,7 +346,29 @@ def global_subscribe(last_id = nil, &blk)
       private
 
       def new_redis_connection
-        ::Redis.new(@redis_config.dup)
+        config = @redis_config.filter do |k, v|
+          # This is not ideal, required for Redis gem version 5
+          # redis-client no longer accepts arbitrary params
+          # anything unknown will error out.
+          # https://github.com/redis-rb/redis-client/blob/master/lib/redis_client/config.rb#L21-L39
+          #
+          #
+          # We should be doing the opposite and allowlisting params
+          # or splitting the object up. Starting with the smallest change that is backwards compatible
+          ![
+            :backend,
+            :logger,
+            :long_polling_enabled,
+            :backend_options,
+            :base_route,
+            :client_message_filters,
+            :site_id_lookup,
+            :group_id_lookup,
+            :user_id_lookup,
+            :transport_codec
+          ].include?(k)
+        end
+        ::Redis.new(config)
       end
 
       # redis connection used for publishing messages

message_bus.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'rack', '>= 1.1.3'
 
   # Optional runtime dependencies
-  gem.add_development_dependency 'redis', '< 5.0'
+  gem.add_development_dependency 'redis'
   gem.add_development_dependency 'pg'
   gem.add_development_dependency 'concurrent-ruby' # for distributed-cache
 

spec/lib/message_bus/backend_spec.rb

@@ -392,11 +392,4 @@
     got.map { |m| m.data }.must_equal ["12"]
   end
 
-  it 'should not lose redis config' do
-    test_only :redis
-    redis_config = { connector: Redis::Client::Connector }
-    @bus.instance_variable_set(:@redis_config, redis_config)
-    @bus.send(:new_redis_connection)
-    expect(@bus.instance_variable_get(:@redis_config)[:connector]).must_equal Redis::Client::Connector
-  end
 end