From 7f91cf1dc60c13d1f072824b21811c749353552c Mon Sep 17 00:00:00 2001
From: Yusuke Endoh <mame@ruby-lang.org>
Date: Mon, 13 Apr 2026 18:34:16 +0900
Subject: [PATCH] Fix NoMethodError in AST diff for record types

SigTyRecordNode stored its fields as a Hash subnode, but the diff
method only handles Node and Array subnodes. Split @fields into
@keys (attrs) and @vals (subnodes) so diff works correctly when
editing code with inline record type annotations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 lib/typeprof/core/ast/sig_type.rb | 24 +++++++++++++-----------
 scenario/rbs/record-diff.rb       | 18 ++++++++++++++++++
 2 files changed, 31 insertions(+), 11 deletions(-)
 create mode 100644 scenario/rbs/record-diff.rb

diff --git a/lib/typeprof/core/ast/sig_type.rb b/lib/typeprof/core/ast/sig_type.rb
index cca910ac..009e1305 100644
--- a/lib/typeprof/core/ast/sig_type.rb
+++ b/lib/typeprof/core/ast/sig_type.rb
@@ -766,16 +766,18 @@ def show
     class SigTyRecordNode < SigTyNode
       def initialize(raw_decl, lenv)
         super(raw_decl, lenv)
-        @fields = raw_decl.fields.transform_values { |val| AST.create_rbs_type(val, lenv) }
+        @keys = raw_decl.fields.keys
+        @vals = raw_decl.fields.values.map { |val| AST.create_rbs_type(val, lenv) }
       end
 
-      attr_reader :fields
-      def subnodes = { fields: }
+      attr_reader :keys, :vals
+      def subnodes = { vals: }
+      def attrs = { keys: }
 
       def covariant_vertex0(genv, changes, vtx, subst)
         field_vertices = {}
-        @fields.each do |key, field_node|
-          field_vertices[key] = field_node.covariant_vertex(genv, changes, subst)
+        @keys.zip(@vals) do |key, val_node|
+          field_vertices[key] = val_node.covariant_vertex(genv, changes, subst)
         end
 
         # Create base Hash type for Record
@@ -792,8 +794,8 @@ def covariant_vertex0(genv, changes, vtx, subst)
 
       def contravariant_vertex0(genv, changes, vtx, subst)
         field_vertices = {}
-        @fields.each do |key, field_node|
-          field_vertices[key] = field_node.contravariant_vertex(genv, changes, subst)
+        @keys.zip(@vals) do |key, val_node|
+          field_vertices[key] = val_node.contravariant_vertex(genv, changes, subst)
         end
 
         # Create base Hash type for Record
@@ -816,9 +818,9 @@ def typecheck(genv, changes, vtx, subst)
           found_any = true
           case ty
           when Type::Hash
-            @fields.each do |key, field_node|
+            @keys.zip(@vals) do |key, val_node|
               val_vtx = ty.get_value(key)
-              return false unless field_node.typecheck(genv, changes, val_vtx, subst)
+              return false unless val_node.typecheck(genv, changes, val_vtx, subst)
             end
             return true
           end
@@ -827,8 +829,8 @@ def typecheck(genv, changes, vtx, subst)
       end
 
       def show
-        field_strs = @fields.map do |key, field_node|
-          "#{ key }: #{ field_node.show }"
+        field_strs = @keys.zip(@vals).map do |key, val_node|
+          "#{ key }: #{ val_node.show }"
         end
         "{ #{ field_strs.join(", ") } }"
       end
diff --git a/scenario/rbs/record-diff.rb b/scenario/rbs/record-diff.rb
new file mode 100644
index 00000000..5d7a8f56
--- /dev/null
+++ b/scenario/rbs/record-diff.rb
@@ -0,0 +1,18 @@
+## update: test.rb
+#: ({ name: String, age: Integer }) -> void
+def accept_user(user)
+  name = user[:name]
+  age = user[:age]
+end
+
+## update: test.rb
+#: ({ name: String, age: Integer }) -> void
+def accept_user(user)
+  name = user[:name]
+  age = user[:age]
+end
+
+## assert: test.rb
+class Object
+  def accept_user: ({ name: String, age: Integer }) -> (Integer | Object)
+end