[Tapioca Add-on] Generate DSL RBIs in add-on mode

lib/ruby_lsp/tapioca/addon.rb

@@ -12,6 +12,8 @@
   return
 end
 
+require "zlib"
+
 module RubyLsp
   module Tapioca
     class Addon < ::RubyLsp::Addon
@@ -23,24 +25,33 @@ def initialize
 
         @global_state = T.let(nil, T.nilable(RubyLsp::GlobalState))
         @rails_runner_client = T.let(nil, T.nilable(RubyLsp::Rails::RunnerClient))
+        @index = T.let(nil, T.nilable(RubyIndexer::Index))
+        @file_checksums = T.let({}, T::Hash[String, String])
+        @outgoing_queue = T.let(nil, T.nilable(Thread::Queue))
       end
 
       sig { override.params(global_state: RubyLsp::GlobalState, outgoing_queue: Thread::Queue).void }
       def activate(global_state, outgoing_queue)
         @global_state = global_state
         return unless @global_state.enabled_feature?(:tapiocaAddon)
 
+        @index = @global_state.index
+        @outgoing_queue = outgoing_queue
         Thread.new do
           # Get a handle to the Rails add-on's runtime client. The call to `rails_runner_client` will block this thread
           # until the server has finished booting, but it will not block the main LSP. This has to happen inside of a
           # thread
           addon = T.cast(::RubyLsp::Addon.get("Ruby LSP Rails", ">= 0.3.17", "< 0.4"), ::RubyLsp::Rails::Addon)
           @rails_runner_client = addon.rails_runner_client
-          outgoing_queue << Notification.window_log_message("Activating Tapioca add-on v#{version}")
+          @outgoing_queue << Notification.window_log_message("Activating Tapioca add-on v#{version}")
           @rails_runner_client.register_server_addon(File.expand_path("server_addon.rb", __dir__))
         rescue IncompatibleApiError
           # The requested version for the Rails add-on no longer matches. We need to upgrade and fix the breaking
           # changes
+          @outgoing_queue << Notification.window_log_message(
+            "IncompatibleApiError: Cannot activate Tapioca LSP add-on",
+            type: Constant::MessageType::WARNING,
+          )
         end
       end
 
@@ -63,7 +74,58 @@ def workspace_did_change_watched_files(changes)
         return unless T.must(@global_state).enabled_feature?(:tapiocaAddon)
         return unless @rails_runner_client # Client is not ready
 
-        nil
+        constants = changes.flat_map do |change|
+          path = URI(change[:uri]).to_standardized_path
+          next if path.end_with?("_test.rb", "_spec.rb")
+          next unless file_updated?(change, path)
+
+          entries = T.must(@index).entries_for(path)
+          next unless entries
+
+          entries.filter_map do |entry|
+            entry.name if entry.class == RubyIndexer::Entry::Class || entry.class == RubyIndexer::Entry::Module
+          end
+        end.compact
+
+        return if constants.empty?
+
+        @rails_runner_client.trigger_reload
+        @rails_runner_client.delegate_notification(
+          server_addon_name: "Tapioca",
+          request_name: "dsl",
+          constants: constants,
+        )
+      end
+
+      private
+
+      sig { params(change: T::Hash[Symbol, T.untyped], path: String).returns(T::Boolean) }
+      def file_updated?(change, path)
+        case change[:type]
+        when Constant::FileChangeType::CREATED
+          @file_checksums[path] = Zlib.crc32(File.read(path)).to_s
+          return true
+        when Constant::FileChangeType::CHANGED
+          current_checksum = Zlib.crc32(File.read(path)).to_s
+          if @file_checksums[path] == current_checksum
+            T.must(@outgoing_queue) << Notification.window_log_message(
+              "File has not changed. Skipping #{path}",
+              type: Constant::MessageType::INFO,
+            )
+          else
+            @file_checksums[path] = current_checksum
+            return true
+          end
+        when Constant::FileChangeType::DELETED
+          @file_checksums.delete(path)
+        else
+          T.must(@outgoing_queue) << Notification.window_log_message(
+            "Unexpected file change type: #{change[:type]}",
+            type: Constant::MessageType::WARNING,
+          )
+        end
+
+        false
       end
     end
   end

lib/ruby_lsp/tapioca/server_addon.rb

@@ -13,13 +13,17 @@ def name
       def execute(request, params)
         case request
         when "dsl"
-          dsl(params)
+          fork do
+            dsl(params)
+          end
         end
       end
 
       private
 
       def dsl(params)
+        load("tapioca/cli.rb") # Reload the CLI to reset thor defaults between requests
+        ::Tapioca::Cli.start(["dsl", "--lsp_addon", "--workers=1"] + params[:constants])
       end
     end
   end

lib/tapioca/commands/abstract_dsl.rb

@@ -77,6 +77,10 @@ def initialize(
 
       sig { params(outpath: Pathname, quiet: T::Boolean).returns(T::Set[Pathname]) }
       def generate_dsl_rbi_files(outpath, quiet:)
+        if @lsp_addon
+          pipeline.active_compilers.each(&:reset_state)
+        end
+
         existing_rbi_files = existing_rbi_filenames(all_requested_constants)
 
         generated_files = pipeline.run do |constant, contents|

lib/tapioca/dsl/compiler.rb

@@ -51,6 +51,13 @@ def requested_constants=(constants)
           @@requested_constants = constants # rubocop:disable Style/ClassVars
         end
 
+        sig { void }
+        def reset_state
+          @processable_constants = nil
+          @all_classes = nil
+          @all_modules = nil
+        end
+
         private
 
         sig do

sorbet/rbi/shims/uri.rbi

@@ -16,4 +16,9 @@ module URI
     sig { returns(String) }
     attr_reader :fragment
   end
+
+  class Generic
+    sig { returns(String) }
+    def to_standardized_path; end
+  end
 end