Add textDocument/references handler in master

Orchestrate two-phase find references: send ResolveSymbol to the
interaction worker to resolve the cursor position, then broadcast
References__Search to all typecheck workers and merge results.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: soutaro

lib/steep/server/master.rb

@@ -386,7 +386,8 @@ def process_message_from_client(message)
                       definition_provider: true,
                       declaration_provider: false,
                       implementation_provider: true,
-                      type_definition_provider: true
+                      type_definition_provider: true,
+                      references_provider: true
                     ),
                     server_info: {
                       name: "steep",
@@ -664,6 +665,56 @@ def process_message_from_client(message)
             end
           end
 
+        when "textDocument/references"
+          if interaction_worker && pathname(message[:params][:textDocument][:uri])
+            result_controller << send_request(
+              method: CustomMethods::ResolveSymbol::METHOD,
+              params: message[:params],
+              worker: interaction_worker
+            ) do |handler|
+              handler.on_completion do |response|
+                queries = response[:result] || []
+
+                if queries.empty?
+                  enqueue_write_job SendMessageJob.to_client(
+                    message: {
+                      id: message[:id],
+                      result: [] #: Array[untyped]
+                    }
+                  )
+                else
+                  include_declaration = message[:params].dig(:context, :includeDeclaration) || false
+                  search_params = { queries: queries, include_declaration: include_declaration }
+
+                  result_controller << group_request do |group|
+                    typecheck_workers.each do |worker|
+                      group << send_request(
+                        method: CustomMethods::References__Search::METHOD,
+                        params: search_params,
+                        worker: worker
+                      )
+                    end
+
+                    group.on_completion do |handlers|
+                      links = handlers.flat_map(&:result)
+                      links.uniq!
+                      enqueue_write_job SendMessageJob.to_client(
+                        message: { id: message[:id], result: links }
+                      )
+                    end
+                  end
+                end
+              end
+            end
+          else
+            enqueue_write_job SendMessageJob.to_client(
+              message: {
+                id: message[:id],
+                result: [] #: Array[untyped]
+              }
+            )
+          end
+
         when CustomMethods::TypeCheck::METHOD
           id = message[:id]
           params = message[:params] #: CustomMethods::TypeCheck::params

sig/steep/server/custom_methods.rbs

@@ -138,21 +138,10 @@ module Steep
         def self.response: (String id, result) -> untyped
       end
 
-      type position = { line: Integer, character: Integer }
-
-      type range = { start: position, end: position }
-
-      # LSP TextDocumentPositionParams
-      type text_document_position = {
-        textDocument: { uri: String },
-        position: position
-      }
-
-      type link = { uri: String, range: range }
-
-      # Request to resolve a cursor position into a symbol name
+      # Request to resolve references queries from a position
       #
-      # Sent from the master to the interaction worker.
+      # Sent from the master to the interaction worker. The interaction worker resolves
+      # the cursor position into a symbol that the typecheck workers can search.
       #
       module ResolveSymbol
         METHOD: String
@@ -173,23 +162,31 @@ module Steep
         def self.response: (String id, result) -> untyped
       end
 
-      # Request to search for references matching a resolved symbol
+      type position = { line: Integer, character: Integer }
+
+      type range = { start: position, end: position }
+
+      type text_document_position = {
+        textDocument: { uri: String },
+        position: position
+      }
+
+      type link = { uri: String, range: range }
+
+      # Request to search for references matching resolved queries
       #
       # Sent from the master to typecheck workers. Each worker searches its assigned
       # files and returns matching locations.
       #
       module References__Search
         METHOD: String
 
-        type params = {
-          query: String,
-          include_declaration: bool
-        }
-
-        type result = Array[link]
+        type params = String
 
         def self.request: (String id, params) -> untyped
 
+        type result = Array[link]
+
         def self.response: (String id, result) -> untyped
       end