Test(rollout): add unit tests for vllm_rollout helpers and mocked generate paths

tests/unit/rollout/conftest.py

@@ -0,0 +1,65 @@
+"""Shared stubs for ``slime.rollout.vllm_rollout`` unit tests."""
+
+from __future__ import annotations
+
+import sys
+import types
+from unittest.mock import MagicMock
+
+
+def _ensure_vllm_router_stub() -> None:
+    if "vllm_router" in sys.modules:
+        return
+    sys.modules["vllm_router"] = types.ModuleType("vllm_router")
+
+
+def _ensure_pil_stub() -> None:
+    if "PIL" in sys.modules:
+        return
+    pil = types.ModuleType("PIL")
+    image_mod = types.ModuleType("PIL.Image")
+    pil.Image = image_mod
+    sys.modules["PIL"] = pil
+    sys.modules["PIL.Image"] = image_mod
+
+
+def _ensure_transformers_stub() -> None:
+    if "transformers" in sys.modules:
+        return
+    mod = types.ModuleType("transformers")
+    mod.AutoTokenizer = type(
+        "AutoTokenizer",
+        (),
+        {"from_pretrained": staticmethod(lambda *args, **kwargs: object())},
+    )
+    mod.AutoProcessor = type(
+        "AutoProcessor",
+        (),
+        {"from_pretrained": staticmethod(lambda *args, **kwargs: (_ for _ in ()).throw(OSError()))},
+    )
+    mod.PreTrainedTokenizerBase = type("PreTrainedTokenizerBase", (), {})
+    mod.ProcessorMixin = type("ProcessorMixin", (), {})
+    sys.modules["transformers"] = mod
+
+
+def _ensure_aiohttp_stub() -> None:
+    if "aiohttp" in sys.modules:
+        return
+    sys.modules["aiohttp"] = MagicMock()
+
+
+def _ensure_pylatexenc_stub() -> None:
+    if "pylatexenc" in sys.modules:
+        return
+    pylatexenc = types.ModuleType("pylatexenc")
+    latex2text = types.ModuleType("pylatexenc.latex2text")
+    pylatexenc.latex2text = latex2text
+    sys.modules["pylatexenc"] = pylatexenc
+    sys.modules["pylatexenc.latex2text"] = latex2text
+
+
+_ensure_vllm_router_stub()
+_ensure_pil_stub()
+_ensure_transformers_stub()
+_ensure_aiohttp_stub()
+_ensure_pylatexenc_stub()