feat: support compatibility with redis gem (#84)

Author: supercaracal

lib/redis_client/cluster.rb

@@ -11,6 +11,7 @@ class Cluster
 
     def initialize(config, pool: nil, **kwargs)
       @router = ::RedisClient::Cluster::Router.new(config, pool: pool, **kwargs)
+      @command_builder = config.command_builder
     end
 
     def inspect
@@ -71,5 +72,25 @@ def close
       @router.node.call_all(:close)
       nil
     end
+
+    private
+
+    def method_missing(name, *args, **kwargs)
+      if @router.command_exists?(name)
+        args.unshift(name)
+        args = @command_builder.generate!(args, kwargs)
+        @router.send_command(:call, *args)
+      else
+        super
+      end
+    end
+
+    def respond_to_missing?(name, include_private = false)
+      if @router.command_exists?(name)
+        true
+      else
+        super
+      end
+    end
   end
 end

lib/redis_client/cluster/command.rb

@@ -55,6 +55,10 @@ def should_send_to_replica?(command)
         dig_details(command, :readonly)
       end
 
+      def exists?(name)
+        @details.key?(name.to_s.downcase)
+      end
+
       private
 
       def pick_details(details)

lib/redis_client/cluster/router.rb

@@ -142,6 +142,10 @@ def find_node(node_key, retry_count: 3)
         retry
       end
 
+      def command_exists?(name)
+        @command.exists?(name)
+      end
+
       private
 
       def send_wait_command(method, *args, retry_count: 3, **kwargs, &block)

lib/redis_client/cluster_config.rb

@@ -4,6 +4,7 @@
 require 'redis_client'
 require 'redis_client/cluster'
 require 'redis_client/cluster/node_key'
+require 'redis_client/command_builder'
 
 class RedisClient
   class ClusterConfig
@@ -19,11 +20,14 @@ class ClusterConfig
 
     InvalidClientConfigError = Class.new(::RedisClient::Error)
 
+    attr_reader :command_builder
+
     def initialize(nodes: DEFAULT_NODES, replica: false, fixed_hostname: '', **client_config)
       @replica = true & replica
       @fixed_hostname = fixed_hostname.to_s
       @node_configs = build_node_configs(nodes.dup)
       client_config = client_config.reject { |k, _| IGNORE_GENERIC_CONFIG_KEYS.include?(k) }
+      @command_builder = client_config.fetch(:command_builder, ::RedisClient::CommandBuilder)
       @client_config = merge_generic_config(client_config, @node_configs)
       @mutex = Mutex.new
     end

test/redis_client/cluster/test_command.rb

@@ -115,6 +115,25 @@ def test_should_send_to_replica?
         end
       end
 
+      def test_exists?
+        cmd = ::RedisClient::Cluster::Command.load(@raw_clients)
+        [
+          { name: 'ping', want: true },
+          { name: :ping, want: true },
+          { name: 'PING', want: true },
+          { name: 'densaugeo', want: false },
+          { name: :densaugeo, want: false },
+          { name: 'DENSAUGEO', want: false },
+          { name: '', want: false },
+          { name: 0, want: false },
+          { name: nil, want: false }
+        ].each_with_index do |c, idx|
+          msg = "Case: #{idx}"
+          got = cmd.exists?(c[:name])
+          assert_equal(c[:want], got, msg)
+        end
+      end
+
       def test_pick_details
         keys = %i[first_key_position write readonly].freeze
         [

test/redis_client/test_cluster.rb

@@ -182,6 +182,12 @@ def test_dedicated_commands
         end
       end
 
+      def test_compatibility_with_redis_gem
+        assert_equal('OK', @client.set('foo', 100))
+        assert_equal('100', @client.get('foo'))
+        assert_raises(NoMethodError) { @client.densaugeo('1m') }
+      end
+
       private
 
       def wait_for_replication

test/redis_client/test_cluster_config.rb

@@ -90,6 +90,10 @@ def test_dup
       refute_equal(orig.object_id, copy.object_id)
     end
 
+    def test_command_builder
+      assert_equal(::RedisClient::CommandBuilder, ::RedisClient::ClusterConfig.new.command_builder)
+    end
+
     def test_build_node_configs
       config = ::RedisClient::ClusterConfig.new
       [