[AMD][Spec] Fix aiter GQA packing + split-KV routing in NEXTN spec attention (verify & draft_extend) (#30105)

test/manual/test_aiter_unified_draft_extend_env.py

@@ -0,0 +1,40 @@
+"""
+Unit test for the aiter NEXTN spec-decode draft_extend routing flag.
+
+aiter_backend.py routes EAGLE-v2 draft_extend (KV catch-up) through
+unified_attention (GQA-packed + split-KV) instead of the occupancy-starved
+mha_batch_prefill FMHA, gated behind SGLANG_AITER_UNIFIED_DRAFT_EXTEND. This
+guards the flag's registration and default so an accidental rename or default
+flip is caught in CI. The kernel path itself requires ROCm/gfx950 and is
+covered by the accuracy/speed evidence in the PR.
+
+Run:
+    python test/manual/test_aiter_unified_draft_extend_env.py
+"""
+
+import os
+import sys
+import unittest
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "../../python"))
+
+
+class TestAiterUnifiedDraftExtendEnv(unittest.TestCase):
+    def setUp(self):
+        from sglang.srt.environ import envs
+
+        self.flag = envs.SGLANG_AITER_UNIFIED_DRAFT_EXTEND
+
+    def test_registered_and_default_on(self):
+        # Registered as an EnvBool defaulting to True (path enabled in prod).
+        self.assertTrue(self.flag.get())
+
+    def test_override_toggles_and_restores(self):
+        self.assertTrue(self.flag.get())
+        with self.flag.override(False):
+            self.assertFalse(self.flag.get())
+        self.assertTrue(self.flag.get())
+
+
+if __name__ == "__main__":
+    unittest.main()