Make instanec of RunnerClient accessible for addons

Author: johansenja

lib/ruby_lsp/ruby_lsp_rails/runner_client.rb

@@ -7,24 +7,29 @@
 module RubyLsp
   module Rails
     class RunnerClient
+      @instance = T.let(nil, T.nilable(RunnerClient))
+
       class << self
         extend T::Sig
 
+        sig { returns(T.nilable(RunnerClient)) }
+        attr_reader :instance
+
         sig { returns(RunnerClient) }
         def create_client
           if File.exist?("bin/rails")
-            new
+            @instance = new
           else
             $stderr.puts(<<~MSG)
               Ruby LSP Rails failed to locate bin/rails in the current directory: #{Dir.pwd}"
             MSG
             $stderr.puts("Server dependent features will not be available")
-            NullClient.new
+            @instance = NullClient.new
           end
         rescue Errno::ENOENT, StandardError => e # rubocop:disable Lint/ShadowedException
           $stderr.puts("Ruby LSP Rails failed to initialize server: #{e.message}\n#{e.backtrace&.join("\n")}")
           $stderr.puts("Server dependent features will not be available")
-          NullClient.new
+          @instance = NullClient.new
         end
       end
 
@@ -169,6 +174,22 @@ def stopped?
         [@stdin, @stdout, @stderr].all?(&:closed?) && !@wait_thread.alive?
       end
 
+      sig do
+        params(
+          server_addon_name: String,
+          request_name: String,
+          params: T.nilable(T::Hash[Symbol, T.untyped])
+        ).returns(T.nilable(T::Hash[Symbol, T.untyped]))
+      end
+      def make_addon_request(server_addon_name, request_name, **params)
+        make_request(
+          "server_addon/delegate",
+          server_addon_name:,
+          request_name:,
+          **params
+        )
+      end
+
       sig do
         params(
           request: String,