[Fix] Skip intentional race tests under ThreadSanitizer

Tests that intentionally trigger data races to document unsafe patterns
(ConcurrentEdgeAdditions, MixedReadWriteOperations) are now skipped
when running under TSAN since TSAN will detect the races and abort.

The RUNNING_UNDER_TSAN macro detects both GCC/Clang TSAN instrumentation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: rxdu

tests/unit_test/thread_safety_test.cpp

@@ -16,6 +16,19 @@
 
 #include "gtest/gtest.h"
 
+// Detect if running under ThreadSanitizer
+// Tests that intentionally trigger races should be skipped under TSAN
+#if defined(__SANITIZE_THREAD__)
+  #define RUNNING_UNDER_TSAN 1
+#elif defined(__has_feature)
+  #if __has_feature(thread_sanitizer)
+    #define RUNNING_UNDER_TSAN 1
+  #endif
+#endif
+#ifndef RUNNING_UNDER_TSAN
+  #define RUNNING_UNDER_TSAN 0
+#endif
+
 #include "graph/graph.hpp"
 #include "graph/tree.hpp"
 #include "graph/search/astar.hpp"
@@ -232,8 +245,14 @@ TEST_F(ThreadSafetyTest, DISABLED_ConcurrentVertexAdditions) {
 }
 
 TEST_F(ThreadSafetyTest, ConcurrentEdgeAdditions) {
+  // This test intentionally triggers race conditions to document unsafe patterns
+  // Skip under TSAN since it will detect the intentional races and abort
+  if (RUNNING_UNDER_TSAN) {
+    GTEST_SKIP() << "Skipping intentional race test under ThreadSanitizer";
+  }
+
   Graph<ThreadSafeState> graph;
-  
+
   // Pre-create vertices
   const int VERTEX_COUNT = 20;
   for (int i = 0; i < VERTEX_COUNT; ++i) {
@@ -276,8 +295,14 @@ TEST_F(ThreadSafetyTest, ConcurrentEdgeAdditions) {
 // ===== MIXED READ/WRITE OPERATIONS =====
 
 TEST_F(ThreadSafetyTest, MixedReadWriteOperations) {
+  // This test intentionally triggers race conditions to document unsafe patterns
+  // Skip under TSAN since it will detect the intentional races and abort
+  if (RUNNING_UNDER_TSAN) {
+    GTEST_SKIP() << "Skipping intentional race test under ThreadSanitizer";
+  }
+
   Graph<ThreadSafeState> graph;
-  
+
   // Pre-populate with some vertices
   for (int i = 0; i < 50; ++i) {
     graph.AddVertex(ThreadSafeState(i));