Mask API key for baidu qianfan (#14281)

Description: This PR masked baidu qianfan - Chat_Models API Key and
added unit tests.
Issue: the issue langchain-ai#12165.
Tag maintainer: @eyurtsev

---------

Co-authored-by: xiayi <xiayi@bytedance.com>

libs/langchain/langchain/chat_models/baidu_qianfan_endpoint.py

@@ -13,7 +13,8 @@ from langchain_core.messages import (
     SystemMessage,
 )
 from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult
-from langchain_core.pydantic_v1 import Field, root_validator
+from langchain_core.pydantic_v1 import Field, SecretStr, root_validator
+from langchain_core.utils import convert_to_secret_str
 
 from langchain.callbacks.manager import (
     AsyncCallbackManagerForLLMRun,
@@ -88,8 +89,8 @@ class QianfanChatEndpoint(BaseChatModel):
 
     client: Any
 
-    qianfan_ak: Optional[str] = None
-    qianfan_sk: Optional[str] = None
+    qianfan_ak: Optional[SecretStr] = None
+    qianfan_sk: Optional[SecretStr] = None
 
     streaming: Optional[bool] = False
     """Whether to stream the results or not."""
@@ -118,19 +119,23 @@ class QianfanChatEndpoint(BaseChatModel):
 
     @root_validator()
     def validate_environment(cls, values: Dict) -> Dict:
-        values["qianfan_ak"] = get_from_dict_or_env(
-            values,
-            "qianfan_ak",
-            "QIANFAN_AK",
+        values["qianfan_ak"] = convert_to_secret_str(
+            get_from_dict_or_env(
+                values,
+                "qianfan_ak",
+                "QIANFAN_AK",
+            )
         )
-        values["qianfan_sk"] = get_from_dict_or_env(
-            values,
-            "qianfan_sk",
-            "QIANFAN_SK",
+        values["qianfan_sk"] = convert_to_secret_str(
+            get_from_dict_or_env(
+                values,
+                "qianfan_sk",
+                "QIANFAN_SK",
+            )
         )
         params = {
-            "ak": values["qianfan_ak"],
-            "sk": values["qianfan_sk"],
+            "ak": values["qianfan_ak"].get_secret_value(),
+            "sk": values["qianfan_sk"].get_secret_value(),
             "model": values["model"],
             "stream": values["streaming"],
         }

libs/langchain/tests/integration_tests/chat_models/test_baiduqianfan.py

@@ -0,0 +1,53 @@
+from typing import cast
+
+from langchain_core.pydantic_v1 import SecretStr
+from pytest import CaptureFixture, MonkeyPatch
+
+from langchain.chat_models.baidu_qianfan_endpoint import (
+    QianfanChatEndpoint,
+)
+
+
+def test_qianfan_key_masked_when_passed_from_env(
+    monkeypatch: MonkeyPatch, capsys: CaptureFixture
+) -> None:
+    """Test initialization with an API key provided via an env variable"""
+    monkeypatch.setenv("QIANFAN_AK", "test-api-key")
+    monkeypatch.setenv("QIANFAN_SK", "test-secret-key")
+
+    chat = QianfanChatEndpoint()
+    print(chat.qianfan_ak, end="")
+    captured = capsys.readouterr()
+    assert captured.out == "**********"
+
+    print(chat.qianfan_sk, end="")
+    captured = capsys.readouterr()
+    assert captured.out == "**********"
+
+
+def test_qianfan_key_masked_when_passed_via_constructor(
+    capsys: CaptureFixture,
+) -> None:
+    """Test initialization with an API key provided via the initializer"""
+    chat = QianfanChatEndpoint(
+        qianfan_ak="test-api-key",
+        qianfan_sk="test-secret-key",
+    )
+    print(chat.qianfan_ak, end="")
+    captured = capsys.readouterr()
+    assert captured.out == "**********"
+
+    print(chat.qianfan_sk, end="")
+    captured = capsys.readouterr()
+
+    assert captured.out == "**********"
+
+
+def test_uses_actual_secret_value_from_secret_str() -> None:
+    """Test that actual secret is retrieved using `.get_secret_value()`."""
+    chat = QianfanChatEndpoint(
+        qianfan_ak="test-api-key",
+        qianfan_sk="test-secret-key",
+    )
+    assert cast(SecretStr, chat.qianfan_ak).get_secret_value() == "test-api-key"
+    assert cast(SecretStr, chat.qianfan_sk).get_secret_value() == "test-secret-key"