From 5e5f2a6de17681f03075b0b83e889581661a561a Mon Sep 17 00:00:00 2001
From: ksss <co000ri@gmail.com>
Date: Wed, 21 Jan 2026 11:59:08 +0900
Subject: [PATCH 1/3] Setup test with ASAN

---
 .github/workflows/ruby.yml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 30cead014..ff4dab374 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -32,6 +32,8 @@ jobs:
             job: rubocop validate test_doc build test_generate_stdlib raap
           - ruby: "4.0"
             job: typecheck_test
+          - ruby: asan-release
+            job: test
     env:
       RANDOMIZE_STDLIB_TEST_ORDER: "true"
     steps:
@@ -66,6 +68,10 @@ jobs:
       - name: bin/setup
         run: |
           bin/setup
+      - name: Configure ASAN options
+        if: ${{ contains(matrix.ruby, 'asan') }}
+        run: |
+          echo "ASAN_OPTIONS=abort_on_error=1" >> $GITHUB_ENV
       - name: Run test
         run: |
           bundle exec rake ${{ matrix.job }}

From 951e57dc21ae17c9e22b16f193f91a7199ed9c10 Mon Sep 17 00:00:00 2001
From: ksss <co000ri@gmail.com>
Date: Wed, 21 Jan 2026 11:59:38 +0900
Subject: [PATCH 2/3] Try asan

---
 ext/rbs_extension/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ext/rbs_extension/main.c b/ext/rbs_extension/main.c
index 7f21237d2..41219930f 100644
--- a/ext/rbs_extension/main.c
+++ b/ext/rbs_extension/main.c
@@ -466,6 +466,10 @@ void Init_rbs_extension(void) {
 #ifdef HAVE_RB_EXT_RACTOR_SAFE
     rb_ext_ractor_safe(true);
 #endif
+    // ASAN test: intentional heap buffer overflow to verify ASAN is working
+    volatile char *test_ptr = malloc(10);
+    test_ptr[10] = 'A'; // Out of bounds write - this will be caught by ASAN
+
     rbs__init_constants();
     rbs__init_location();
     rbs__init_parser();

From 5fe342c7b7e2776c8edf6773bbae137deaffa510 Mon Sep 17 00:00:00 2001
From: ksss <co000ri@gmail.com>
Date: Wed, 21 Jan 2026 12:04:25 +0900
Subject: [PATCH 3/3] Revert code that fails with ASAN

---
 ext/rbs_extension/main.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/ext/rbs_extension/main.c b/ext/rbs_extension/main.c
index 41219930f..7f21237d2 100644
--- a/ext/rbs_extension/main.c
+++ b/ext/rbs_extension/main.c
@@ -466,10 +466,6 @@ void Init_rbs_extension(void) {
 #ifdef HAVE_RB_EXT_RACTOR_SAFE
     rb_ext_ractor_safe(true);
 #endif
-    // ASAN test: intentional heap buffer overflow to verify ASAN is working
-    volatile char *test_ptr = malloc(10);
-    test_ptr[10] = 'A'; // Out of bounds write - this will be caught by ASAN
-
     rbs__init_constants();
     rbs__init_location();
     rbs__init_parser();