Preserve partial accessor visibility in prototypes

lib/rbs/prototype/rb.rb

@@ -315,9 +315,16 @@ def process(node, decls:, comments:, context:)
             else
               args.each do |arg|
                 if arg && (name = literal_to_symbol(arg))
-                  if (i, _ = find_def_index_by_name(decls, name))
+                  if (i, defn = find_def_index_by_name(decls, name))
                     current = current_accessibility(decls, i)
                     if current != accessibility
+                      if defn.is_a?(AST::Members::AttrAccessor)
+                        reader = build_attribute_member(AST::Members::AttrReader, defn)
+                        writer = build_attribute_member(AST::Members::AttrWriter, defn)
+                        targeted, remaining = name == defn.name ? [reader, writer] : [writer, reader]
+                        decls[i, 1] = [targeted, remaining]
+                      end
+
                       decls.insert(i + 1, current)
                       decls.insert(i, accessibility)
                     end
@@ -791,6 +798,8 @@ def find_def_index_by_name(decls, name)
             decl.name == name
           when AST::Members::AttrWriter
             :"#{decl.name}=" == name
+          when AST::Members::AttrAccessor
+            decl.name == name || :"#{decl.name}=" == name
           end
         end
 
@@ -802,6 +811,19 @@ def find_def_index_by_name(decls, name)
         end
       end
 
+      def build_attribute_member(klass, member)
+        klass.new(
+          name: member.name,
+          type: member.type,
+          ivar_name: member.ivar_name,
+          kind: member.kind,
+          annotations: member.annotations,
+          location: member.location,
+          comment: member.comment,
+          visibility: member.visibility
+        )
+      end
+
       def sort_members!(decls)
         i = 0
         orders = {

sig/prototype/rb.rbs

@@ -90,6 +90,8 @@ module RBS
 
       def find_def_index_by_name: (Array[decl] decls, Symbol name) -> [Integer, AST::Members::MethodDefinition | AST::Members::AttrReader | AST::Members::AttrWriter]?
 
+      def build_attribute_member: (singleton(AST::Members::AttrReader) | singleton(AST::Members::AttrWriter) klass, AST::Members::AttrAccessor member) -> (AST::Members::AttrReader | AST::Members::AttrWriter)
+
       def sort_members!: (Array[decl] decls) -> void
     end
   end