core[patch]: Hide aliases when serializing (langchain-ai#16888)

Currently, if you dump an object initialized with an alias, we'll still
dump the secret values since they're retained in the kwargs

libs/core/langchain_core/load/serializable.py

@@ -143,6 +143,14 @@ def to_json(self) -> Union[SerializedConstructor, SerializedNotImplemented]:
             this = cast(Serializable, self if cls is None else super(cls, self))
 
             secrets.update(this.lc_secrets)
+            # Now also add the aliases for the secrets
+            # This ensures known secret aliases are hidden.
+            # Note: this does NOT hide any other extra kwargs
+            # that are not present in the fields.
+            for key in list(secrets):
+                value = secrets[key]
+                if key in this.__fields__:
+                    secrets[this.__fields__[key].alias] = value
             lc_kwargs.update(this.lc_attributes)
 
         # include all secrets, even if not specified in kwargs

libs/langchain/tests/unit_tests/load/test_dump.py

@@ -1,5 +1,6 @@
 """Test for Serializable base class"""
 
+import json
 import os
 from typing import Any, Dict, List
 from unittest.mock import patch
@@ -11,6 +12,7 @@
 from langchain_core.load.serializable import Serializable
 from langchain_core.prompts.chat import ChatPromptTemplate, HumanMessagePromptTemplate
 from langchain_core.prompts.prompt import PromptTemplate
+from langchain_core.pydantic_v1 import Field, root_validator
 from langchain_core.tracers.langchain import LangChainTracer
 
 from langchain.chains.llm import LLMChain
@@ -167,3 +169,85 @@ def test_person_with_invalid_kwargs() -> None:
     person = Person(secret="hello")
     with pytest.raises(TypeError):
         dumps(person, invalid_kwarg="hello")
+
+
+class TestClass(Serializable):
+    my_favorite_secret: str = Field(alias="my_favorite_secret_alias")
+    my_other_secret: str = Field()
+
+    class Config:
+        """Configuration for this pydantic object."""
+
+        allow_population_by_field_name = True
+
+    @root_validator(pre=True)
+    def get_from_env(cls, values: Dict) -> Dict:
+        """Get the values from the environment."""
+        if "my_favorite_secret" not in values:
+            values["my_favorite_secret"] = os.getenv("MY_FAVORITE_SECRET")
+        if "my_other_secret" not in values:
+            values["my_other_secret"] = os.getenv("MY_OTHER_SECRET")
+        return values
+
+    @classmethod
+    def is_lc_serializable(cls) -> bool:
+        return True
+
+    @classmethod
+    def get_lc_namespace(cls) -> List[str]:
+        return ["my", "special", "namespace"]
+
+    @property
+    def lc_secrets(self) -> Dict[str, str]:
+        return {
+            "my_favorite_secret": "MY_FAVORITE_SECRET",
+            "my_other_secret": "MY_OTHER_SECRET",
+        }
+
+
+def test_aliases_hidden() -> None:
+    test_class = TestClass(my_favorite_secret="hello", my_other_secret="world")
+    dumped = json.loads(dumps(test_class, pretty=True))
+    expected_dump = {
+        "lc": 1,
+        "type": "constructor",
+        "id": ["my", "special", "namespace", "TestClass"],
+        "kwargs": {
+            "my_favorite_secret": {
+                "lc": 1,
+                "type": "secret",
+                "id": ["MY_FAVORITE_SECRET"],
+            },
+            "my_other_secret": {"lc": 1, "type": "secret", "id": ["MY_OTHER_SECRET"]},
+        },
+    }
+    assert dumped == expected_dump
+    # Check while patching the os environment
+    with patch.dict(
+        os.environ, {"MY_FAVORITE_SECRET": "hello", "MY_OTHER_SECRET": "world"}
+    ):
+        test_class = TestClass()
+        dumped = json.loads(dumps(test_class, pretty=True))
+
+    # Check by alias
+    test_class = TestClass(my_favorite_secret_alias="hello", my_other_secret="world")
+    dumped = json.loads(dumps(test_class, pretty=True))
+    expected_dump = {
+        "lc": 1,
+        "type": "constructor",
+        "id": ["my", "special", "namespace", "TestClass"],
+        "kwargs": {
+            "my_favorite_secret": {
+                "lc": 1,
+                "type": "secret",
+                "id": ["MY_FAVORITE_SECRET"],
+            },
+            "my_favorite_secret_alias": {
+                "lc": 1,
+                "type": "secret",
+                "id": ["MY_FAVORITE_SECRET"],
+            },
+            "my_other_secret": {"lc": 1, "type": "secret", "id": ["MY_OTHER_SECRET"]},
+        },
+    }
+    assert dumped == expected_dump