From 4dadb7cc316044f8b85c050ecb5561ea29d5be35 Mon Sep 17 00:00:00 2001
From: Yuki Kurihara <co000ri@gmail.com>
Date: Thu, 19 Jun 2025 06:48:22 +0000
Subject: [PATCH] Merge pull request #2369 from ksss/subtractor-civar

Fix subtraction of civar
---
 lib/rbs/subtractor.rb       |  4 +++-
 test/rbs/subtractor_test.rb | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/lib/rbs/subtractor.rb b/lib/rbs/subtractor.rb
index ed8fa14f1..3d98fba82 100644
--- a/lib/rbs/subtractor.rb
+++ b/lib/rbs/subtractor.rb
@@ -107,7 +107,9 @@ def call(minuend = @minuend, context: nil)
       each_member(owner).any? do |m|
         case m
         when AST::Members::InstanceVariable
-          m.name == name
+          m.name == name && kind == :instance
+        when AST::Members::ClassInstanceVariable
+          m.name == name && kind == :singleton
         when AST::Members::Attribute
           ivar_name = m.ivar_name == false ? nil : m.ivar_name || :"@#{m.name}"
           ivar_name == name && m.kind == kind
diff --git a/test/rbs/subtractor_test.rb b/test/rbs/subtractor_test.rb
index 8d4e9f6e8..0315efdb4 100644
--- a/test/rbs/subtractor_test.rb
+++ b/test/rbs/subtractor_test.rb
@@ -472,6 +472,34 @@ class C
     RBS
   end
 
+  def test_civar
+    decls = to_decls(<<~RBS)
+      class C
+        @v1: untyped
+        self.@v1: untyped
+        @v2: untyped
+        self.@v2: untyped
+      end
+    RBS
+
+    env = to_env(<<~RBS)
+      class C
+        self.@v1: untyped
+      end
+    RBS
+
+    subtracted = RBS::Subtractor.new(decls, env).call
+
+    assert_subtracted <<~RBS, subtracted
+      class C
+        @v1: untyped
+
+        @v2: untyped
+        self.@v2: untyped
+      end
+    RBS
+  end
+
   def test_cvar
     decls = to_decls(<<~RBS)
       class C