[Config] Round 5.1: the published-side readers ask the bags, and a platform fact gets one address (#37086)

test/registered/unit/spec/test_dflash_extra_buffer_lazy.py

@@ -16,6 +16,7 @@ from sglang.test.test_utils import CustomTestCase
 register_cuda_ci(est_time=10, stage="base-b", runner_config="1-gpu-small")
 
 from sglang.srt.model_executor.forward_batch_info import ForwardMode
+from sglang.srt.runtime_context import override_platform
 from sglang.srt.speculative import dflash_info
 from sglang.srt.speculative.dflash_info import DFlashVerifyInput
 
@@ -29,6 +30,9 @@ def _lazy_view(**overrides):
         mamba_track_interval=256,
         page_size=64,
         chunked_prefill_size=None,
+        # The cases name a supported arch, so the view states the backend
+        # rather than the answer.
+        linear_attn_backend="triton",
     )
     for key, value in overrides.items():
         setattr(view, key, value)
@@ -39,15 +43,9 @@ class TestValidateMambaExtraBufferLazyDflash(CustomTestCase):
     """The DFLASH rejection is gone; the neighboring invariants still hold."""
 
     def _validate(self, view):
-        with mock.patch(
-            "sglang.srt.arg_groups.overrides.supports_mamba_cache_extra_buffer",
-            return_value=True,
-        ), mock.patch(
-            # Keep the test runnable on CPU-only hosts: the platform assert is
-            # not what is under test here.
-            "sglang.srt.arg_groups.mamba_hook.is_cuda",
-            return_value=True,
-        ):
+        # Keep the test runnable on CPU-only hosts: the platform assert is
+        # not what is under test here.
+        with override_platform(is_cuda=True):
             validate_mamba_extra_buffer(
                 view,
                 "Qwen3NextForCausalLM",
@@ -81,10 +79,7 @@ class TestValidateMambaExtraBufferLazyDflash(CustomTestCase):
         def _must_not_be_read():
             raise AssertionError("the chunk size was read before page_size resolved")
 
-        with mock.patch(
-            "sglang.srt.arg_groups.overrides.supports_mamba_cache_extra_buffer",
-            return_value=True,
-        ), mock.patch("sglang.srt.arg_groups.mamba_hook.is_cuda", return_value=True):
+        with override_platform(is_cuda=True):
             validate_mamba_extra_buffer(
                 _lazy_view(page_size=None),
                 "Qwen3NextForCausalLM",