fix(llms): preserve reasoning fields in base-to-provider config conversion (#5638)

tests/utils/test_factory.py

@@ -0,0 +1,53 @@
+from unittest.mock import Mock, patch
+
+from mem0.configs.llms.anthropic import AnthropicConfig
+from mem0.configs.llms.aws_bedrock import AWSBedrockConfig
+from mem0.configs.llms.base import BaseLlmConfig
+from mem0.configs.llms.openai import OpenAIConfig
+from mem0.utils.factory import LlmFactory
+
+
+def _capture_config(provider_name, config):
+    """Build an LLM via the factory and return the config it was constructed with."""
+    captured = {}
+
+    def fake_llm_class(built_config):
+        captured["config"] = built_config
+        return Mock()
+
+    with patch("mem0.utils.factory.load_class", return_value=fake_llm_class):
+        LlmFactory.create(provider_name, config)
+
+    return captured["config"]
+
+
+def test_base_to_openai_preserves_reasoning_fields():
+    base_config = BaseLlmConfig(model="o3", reasoning_effort="high", is_reasoning_model=True)
+
+    built = _capture_config("openai", base_config)
+
+    assert isinstance(built, OpenAIConfig)
+    assert built.reasoning_effort == "high"
+    assert built.is_reasoning_model is True
+
+
+def test_base_to_kwargs_provider_preserves_reasoning_fields():
+    # AWSBedrockConfig accepts the reasoning fields via **kwargs, so they must survive.
+    base_config = BaseLlmConfig(model="amazon.nova", reasoning_effort="medium", is_reasoning_model=True)
+
+    built = _capture_config("aws_bedrock", base_config)
+
+    assert isinstance(built, AWSBedrockConfig)
+    assert built.reasoning_effort == "medium"
+    assert built.is_reasoning_model is True
+
+
+def test_base_to_provider_without_reasoning_fields_still_builds():
+    # Anthropic config does not accept reasoning_effort/is_reasoning_model;
+    # the conversion must not forward unsupported kwargs to it.
+    base_config = BaseLlmConfig(model="claude-3-5-sonnet-20240620")
+
+    built = _capture_config("anthropic", base_config)
+
+    assert isinstance(built, AnthropicConfig)
+    assert built.model == "claude-3-5-sonnet-20240620"