refactor(models): retire VLLMConverter aliases

nemo_gym/_moved_paths.py

@@ -838,16 +838,27 @@ def _names(new: str, since: str, names: str) -> dict[str, MovedPath]:
     _listed.update(_renamed)
 
 # ResponsesConverter renamed ChatCompletionsConverter: AnthropicConverter also converts to and from the Responses API.
+# The VLLMConverter aliases go with it: the LiteLLM and Azure OpenAI model servers use the converter too.
 # The chat_completions_converter entries also serve its old module path, nemo_gym.responses_converter.
 _CONVERTER = "nemo_gym.models.chat_completions_converter"
+_VLLM_CONVERTER_ALIASES = {
+    "VLLMConverter": MovedPath(new=f"{_CONVERTER}:ChatCompletionsConverter", since="0.8.0"),
+    "VLLMConverterResponsesToChatCompletionsState": MovedPath(
+        new=f"{_CONVERTER}:ChatCompletionsConverterState", since="0.8.0"
+    ),
+}
 _RENAMED_CONVERTER_NAMES: dict[str, dict[str, MovedPath]] = {
     _CONVERTER: {
         "ResponsesConverter": MovedPath(new=f"{_CONVERTER}:ChatCompletionsConverter", since="0.8.0"),
         "ResponsesConverterState": MovedPath(new=f"{_CONVERTER}:ChatCompletionsConverterState", since="0.8.0"),
+        **_VLLM_CONVERTER_ALIASES,
     },
     "nemo_gym.models": {
         "ResponsesConverter": MovedPath(new=f"{_CONVERTER}:ChatCompletionsConverter", since="0.8.0"),
+        **_VLLM_CONVERTER_ALIASES,
     },
+    # Servers imported the aliases from the vLLM model server, which re-exported them.
+    "responses_api_models.vllm_model.app": _VLLM_CONVERTER_ALIASES,
     "nemo_gym.models.token_capture.completion": {
         "ResponsesConverter": MovedPath(new=f"{_CONVERTER}:ChatCompletionsConverter", since="0.8.0"),
     },

nemo_gym/models/__init__.py

@@ -38,8 +38,6 @@
     )
     from nemo_gym.models.chat_completions_converter import (
         ChatCompletionsConverter,
-        VLLMConverter,
-        VLLMConverterResponsesToChatCompletionsState,
         chat_completion_usage_to_response_usage,
         message_content_to_text,
         split_responses_input_output_items,
@@ -78,8 +76,6 @@
     "PROPAGATED_REFUSAL_CODE_ATTRIBUTE": "base_responses_api_model",
     "PolicyModelParticipant": "_checkpoint",
     "SimpleResponsesAPIModel": "base_responses_api_model",
-    "VLLMConverter": "chat_completions_converter",
-    "VLLMConverterResponsesToChatCompletionsState": "chat_completions_converter",
     "VLLMWorkerCaptureHandler": "token_capture.external_capture",
     "chat_completion_usage_to_response_usage": "chat_completions_converter",
     "context_overflow_error_fields": "base_responses_api_model",

nemo_gym/models/chat_completions_converter.py

@@ -1417,9 +1417,5 @@ def split_responses_input_output_items(
     return items[:split_at], items[split_at:]
 
 
-# Backward-compatible aliases
-VLLMConverter = ChatCompletionsConverter
-VLLMConverterResponsesToChatCompletionsState = ChatCompletionsConverterState
-
-# Names this module had before ResponsesConverter was renamed ChatCompletionsConverter, with a warning.
+# Names this module had before the converter was renamed ChatCompletionsConverter, with a warning.
 __getattr__ = moved_names_getattr(__name__)

responses_api_models/vllm_model/app.py

@@ -32,6 +32,7 @@
 from openai.types.shared import ReasoningEffort
 from pydantic import Field, PositiveFloat, PrivateAttr, TypeAdapter, ValidationError, model_validator
 
+from nemo_gym._moved_paths import moved_names_getattr
 from nemo_gym.client import MAX_NUM_TRIES, SESSION_ID_KEY, NeMoGymAsyncOpenAI
 from nemo_gym.client.http_client import _redacted_url
 from nemo_gym.core import (
@@ -55,8 +56,6 @@
     ChatCompletionsConverter,
     ExternalCaptureHandler,
     SimpleResponsesAPIModel,
-    VLLMConverter,  # noqa: F401  # re-exported for importers of this module
-    VLLMConverterResponsesToChatCompletionsState,  # noqa: F401
     context_overflow_error_fields,
     is_propagated_refusal,
     make_external_capture_handler,
@@ -2575,6 +2574,10 @@ def _note_endpoint_success(self, client: NeMoGymAsyncOpenAI) -> None:
         health.failed_at = None
 
 
+# The VLLMConverter aliases this module re-exported, with a warning naming ChatCompletionsConverter.
+__getattr__ = moved_names_getattr(__name__)
+
+
 if __name__ == "__main__":
     VLLMModel.run_webserver()
 elif is_nemo_gym_fastapi_entrypoint(__file__):

scripts/migrate_imports.py

@@ -189,6 +189,13 @@ def __init__(
             moved_to = self.module_path(module)
             if moved_to != module:
                 self.names.setdefault(moved_to, {}).update(moved)
+        # A name renamed in a module that moved earlier is listed under the new path, and is served at the old one.
+        for module, moved in list(self.names.items()):
+            for old, new in self.modules.items():
+                if module == new or module.startswith(new + "."):
+                    listed = self.names.setdefault(old + module[len(new) :], {})
+                    for name, target in moved.items():
+                        listed.setdefault(name, target)
         dotted = {old: new for old, new in self.modules.items()}
         for module, moved in self.names.items():
             for name, (new_module, new_name) in moved.items():
@@ -361,7 +368,12 @@ def span(node: ast.AST) -> tuple[int, int]:
                         )
                 continue
             # `import nemo_gym.old` needs no statement rewrite: the dotted-path pass below covers it.
-            if not (isinstance(node, ast.ImportFrom) and node.module and node.module.split(".")[0] == "nemo_gym"):
+            # A module outside nemo_gym, such as a server module, is rewritten only when it lists moved names.
+            if not (
+                isinstance(node, ast.ImportFrom)
+                and node.module
+                and (node.module.split(".")[0] == "nemo_gym" or node.module in self.names)
+            ):
                 continue
             start, end = span(node)
             if any(KEEP_LINE_MARKER in lines[i] for i in range(node.lineno - 1, node.end_lineno)):

tests/unit_tests/models/test_chat_completions_converter.py

@@ -50,8 +50,6 @@
 from nemo_gym.models.chat_completions_converter import (
     ChatCompletionsConverter,
     ChatCompletionsConverterState,
-    VLLMConverter,
-    VLLMConverterResponsesToChatCompletionsState,
     _usage_detail,
     chat_completion_usage_to_response_usage,
     split_responses_input_output_items,
@@ -112,16 +110,6 @@ def _fixed_uuid(monkeypatch: pytest.MonkeyPatch):
     monkeypatch.setattr("nemo_gym.models.chat_completions_converter.uuid4", lambda: FakeUUID())
 
 
-# ===========================================================================
-# Backward-compatible aliases
-# ===========================================================================
-
-
-def test_backwards_compatible_aliases():
-    assert VLLMConverter is ChatCompletionsConverter
-    assert VLLMConverterResponsesToChatCompletionsState is ChatCompletionsConverterState
-
-
 def test_usage_detail_ignores_ambiguous_top_level_names():
     usage = {"cached_tokens": 99, "cached_input_tokens": 7, "reasoning_tokens": 88, "reasoning_output_tokens": 3}
     assert _usage_detail(usage, "prompt_tokens_details", "cached_tokens", "cached_input_tokens") == 7

tests/unit_tests/test_moved_paths.py

@@ -787,6 +787,27 @@ def test_package_facade_warns_once_for_a_renamed_name() -> None:
         ("nemo_gym.models", "ResponsesConverter", "ChatCompletionsConverter"),
         ("nemo_gym.models.token_capture.completion", "ResponsesConverter", "ChatCompletionsConverter"),
         ("nemo_gym.token_id_capture.completion", "ResponsesConverter", "ChatCompletionsConverter"),
+        # The vLLM-named aliases, released in 0.7.0 at nemo_gym.responses_converter and the vLLM model server.
+        ("nemo_gym.responses_converter", "VLLMConverter", "ChatCompletionsConverter"),
+        (
+            "nemo_gym.responses_converter",
+            "VLLMConverterResponsesToChatCompletionsState",
+            "ChatCompletionsConverterState",
+        ),
+        ("nemo_gym.models.chat_completions_converter", "VLLMConverter", "ChatCompletionsConverter"),
+        (
+            "nemo_gym.models.chat_completions_converter",
+            "VLLMConverterResponsesToChatCompletionsState",
+            "ChatCompletionsConverterState",
+        ),
+        ("nemo_gym.models", "VLLMConverter", "ChatCompletionsConverter"),
+        ("nemo_gym.models", "VLLMConverterResponsesToChatCompletionsState", "ChatCompletionsConverterState"),
+        ("responses_api_models.vllm_model.app", "VLLMConverter", "ChatCompletionsConverter"),
+        (
+            "responses_api_models.vllm_model.app",
+            "VLLMConverterResponsesToChatCompletionsState",
+            "ChatCompletionsConverterState",
+        ),
     ],
 )
 def test_renamed_converter_resolves_at_each_old_path_with_a_warning(module: str, old_name: str, new_name: str) -> None:

tests/unit_tests/tooling/test_migrate_imports.py

@@ -343,6 +343,41 @@ def test_names_split_out_of_a_module_that_moved_later_are_found_at_its_new_path(
                 "from nemo_gym.models.chat_streaming import stream\n"
             )
 
+    def test_names_renamed_after_their_module_moved_are_found_at_its_old_path_in_one_pass(self) -> None:
+        migrator = migrate_imports.Migrator(
+            {"nemo_gym.responses_converter": "nemo_gym.models.chat_completions_converter"},
+            {
+                "nemo_gym.models.chat_completions_converter": {
+                    "VLLMConverter": ("nemo_gym.models.chat_completions_converter", "ChatCompletionsConverter")
+                }
+            },
+        )
+        once = _python(migrator, "from nemo_gym.responses_converter import VLLMConverter, split\n")
+        assert once == (
+            "from nemo_gym.models.chat_completions_converter import ChatCompletionsConverter as VLLMConverter, split\n"
+        )
+        assert _python(migrator, once) == once
+
+    def test_wrapped_import_from_a_server_module_that_lists_moved_names_is_split(self) -> None:
+        migrator = migrate_imports.Migrator(
+            {},
+            {
+                "responses_api_models.vllm_model.app": {
+                    "VLLMConverter": ("nemo_gym.models.chat_completions_converter", "ChatCompletionsConverter")
+                }
+            },
+        )
+        source = "from responses_api_models.vllm_model.app import (\n    VLLMConverter,\n    VLLMModel,\n)\n"
+        once = _python(migrator, source)
+        assert once == (
+            "from nemo_gym.models.chat_completions_converter import ChatCompletionsConverter as VLLMConverter\n"
+            "from responses_api_models.vllm_model.app import VLLMModel\n"
+        )
+        assert _python(migrator, once) == once
+        # Server modules that list no moved names stay out of the rewrite.
+        other = "from responses_api_models.openai_model.app import (\n    SimpleModelServer,\n)\n"
+        assert _python(migrator, other) == other
+
 
 class TestRewriteText:
     def test_library_reference_urls_are_left_for_the_docs_redirects(self, migrator) -> None: