Sync from v0.13

tests/plugins_tests/test_scheduler_plugins.py

@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import pytest
+
+from vllm.engine.arg_utils import EngineArgs
+from vllm.sampling_params import SamplingParams
+from vllm.v1.core.sched.scheduler import Scheduler
+from vllm.v1.engine.llm_engine import LLMEngine
+
+
+class DummyV1Scheduler(Scheduler):
+    def schedule(self):
+        raise Exception("Exception raised by DummyV1Scheduler")
+
+
+def test_scheduler_plugins_v1(monkeypatch: pytest.MonkeyPatch):
+    with monkeypatch.context() as m:
+        # Explicitly turn off engine multiprocessing so
+        # that the scheduler runs in this process
+        m.setenv("VLLM_ENABLE_V1_MULTIPROCESSING", "0")
+
+        with pytest.raises(Exception) as exception_info:
+            engine_args = EngineArgs(
+                model="facebook/opt-125m",
+                enforce_eager=True,  # reduce test time
+                scheduler_cls=DummyV1Scheduler,
+            )
+
+            engine = LLMEngine.from_engine_args(engine_args=engine_args)
+
+            sampling_params = SamplingParams(max_tokens=1)
+            engine.add_request("0", "foo", sampling_params)
+            engine.step()
+
+        assert str(exception_info.value) == "Exception raised by DummyV1Scheduler"