Sync from v0.13

tests/plugins_tests/test_stats_logger_plugins.py

@@ -0,0 +1,76 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import pytest
+from dummy_stat_logger.dummy_stat_logger import DummyStatLogger
+
+from vllm.config import VllmConfig
+from vllm.engine.arg_utils import AsyncEngineArgs
+from vllm.v1.engine.async_llm import AsyncLLM
+from vllm.v1.metrics.loggers import load_stat_logger_plugin_factories
+
+
+def test_stat_logger_plugin_is_discovered(monkeypatch: pytest.MonkeyPatch):
+    with monkeypatch.context() as m:
+        m.setenv("VLLM_PLUGINS", "dummy_stat_logger")
+
+        factories = load_stat_logger_plugin_factories()
+        assert len(factories) == 1, f"Expected 1 factory, got {len(factories)}"
+        assert factories[0] is DummyStatLogger, (
+            f"Expected DummyStatLogger class, got {factories[0]}"
+        )
+
+        # instantiate and confirm the right type
+        vllm_config = VllmConfig()
+        instance = factories[0](vllm_config)
+        assert isinstance(instance, DummyStatLogger)
+
+
+def test_no_plugins_loaded_if_env_empty(monkeypatch: pytest.MonkeyPatch):
+    with monkeypatch.context() as m:
+        m.setenv("VLLM_PLUGINS", "")
+
+        factories = load_stat_logger_plugin_factories()
+        assert factories == []
+
+
+def test_invalid_stat_logger_plugin_raises(monkeypatch: pytest.MonkeyPatch):
+    def fake_plugin_loader(group: str):
+        assert group == "vllm.stat_logger_plugins"
+        return {"bad": object()}
+
+    with monkeypatch.context() as m:
+        m.setattr(
+            "vllm.v1.metrics.loggers.load_plugins_by_group",
+            fake_plugin_loader,
+        )
+        with pytest.raises(
+            TypeError,
+            match="Stat logger plugin 'bad' must be a subclass of StatLoggerBase",
+        ):
+            load_stat_logger_plugin_factories()
+
+
+@pytest.mark.asyncio
+async def test_stat_logger_plugin_integration_with_engine(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    with monkeypatch.context() as m:
+        m.setenv("VLLM_PLUGINS", "dummy_stat_logger")
+
+        engine_args = AsyncEngineArgs(
+            model="facebook/opt-125m",
+            enforce_eager=True,  # reduce test time
+            disable_log_stats=True,  # disable default loggers
+        )
+
+        engine = AsyncLLM.from_engine_args(engine_args=engine_args)
+
+        assert len(engine.logger_manager.stat_loggers) == 2
+        assert len(engine.logger_manager.stat_loggers[0].per_engine_stat_loggers) == 1
+        assert isinstance(
+            engine.logger_manager.stat_loggers[0].per_engine_stat_loggers[0],
+            DummyStatLogger,
+        )
+
+        engine.shutdown()