[Bugfix] Preserve non-logitproc entry points in tests (#51097)

Signed-off-by: Tristan Rice <rice@fn.lc>

tests/v1/logits_processors/test_custom_offline.py

@@ -1,9 +1,11 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import importlib.metadata
 from typing import Any
 
 import pytest
 
+import tests.v1.logits_processors.utils as logitproc_test_utils
 from tests.utils import create_new_process_for_each_test, set_random_seed
 from tests.v1.logits_processors.utils import (
     DUMMY_LOGITPROC_ARG,
@@ -42,6 +44,32 @@ sampling_params_list = [
 ]
 
 
+def test_fake_entrypoint_preserves_other_groups(monkeypatch):
+    other_group_entrypoints = object()
+    monkeypatch.setattr(
+        importlib.metadata,
+        "entry_points",
+        lambda **kwargs: other_group_entrypoints,
+    )
+    monkeypatch.setattr(
+        logitproc_test_utils, "requires_spawn_multiprocessing", lambda: False
+    )
+
+    setup_fake_entrypoint(monkeypatch)
+
+    logitproc_entrypoints = importlib.metadata.entry_points(
+        group=logitproc_test_utils.LOGITSPROCS_GROUP
+    )
+    assert logitproc_entrypoints.names == [
+        logitproc_test_utils.DUMMY_LOGITPROC_ENTRYPOINT
+    ]
+    assert (
+        importlib.metadata.entry_points(group="another.entrypoint.group")
+        is other_group_entrypoints
+    )
+    assert importlib.metadata.entry_points() is other_group_entrypoints
+
+
 def _run_test(kwargs: dict, logitproc_loaded: bool) -> None:
     """Compare `LLM` instance initialized with specified `kwargs` against
     reference `LLM` instance.

tests/v1/logits_processors/utils.py

@@ -234,11 +234,6 @@ def register_fake_entrypoint(monkeypatch) -> str:
     return str(tmpdir)
 
 
-def fake_entry_points(group: str) -> EntryPoints:
-    """Fake version of importlib.metadata.entry_points."""
-    return EntryPoints(group)
-
-
 def setup_fake_entrypoint(monkeypatch) -> None:
     """Expose the dummy logitproc entrypoint for the current platform."""
     if requires_spawn_multiprocessing():
@@ -248,5 +243,13 @@ def setup_fake_entrypoint(monkeypatch) -> None:
 
     import importlib.metadata
 
+    original_entry_points = importlib.metadata.entry_points
+
+    def fake_entry_points(**kwargs):
+        group = kwargs.get("group")
+        if group == LOGITSPROCS_GROUP:
+            return EntryPoints(group)
+        return original_entry_points(**kwargs)
+
     monkeypatch.setattr(importlib.metadata, "entry_points", fake_entry_points)
     monkeypatch.setenv("VLLM_WORKER_MULTIPROC_METHOD", "fork")