[Core] Support configuration parsing plugin (#24277)

Signed-off-by: Xingyu Liu <charlotteliu12x@gmail.com>
Signed-off-by: Xingyu Liu <38244988+charlotte12l@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

tests/transformers_utils/test_config_parser_registry.py

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from pathlib import Path
+from typing import Optional, Union
+
+import pytest
+from transformers import PretrainedConfig
+
+from vllm.transformers_utils.config import (get_config_parser,
+                                            register_config_parser)
+from vllm.transformers_utils.config_parser_base import ConfigParserBase
+
+
+@register_config_parser("custom_config_parser")
+class CustomConfigParser(ConfigParserBase):
+
+    def parse(self,
+              model: Union[str, Path],
+              trust_remote_code: bool,
+              revision: Optional[str] = None,
+              code_revision: Optional[str] = None,
+              **kwargs) -> tuple[dict, PretrainedConfig]:
+        raise NotImplementedError
+
+
+def test_register_config_parser():
+    assert isinstance(get_config_parser("custom_config_parser"),
+                      CustomConfigParser)
+
+
+def test_invalid_config_parser():
+    with pytest.raises(ValueError):
+
+        @register_config_parser("invalid_config_parser")
+        class InvalidConfigParser:
+            pass