Refactor: use SecretStr for VolcEngineMaas llms (#15117)

libs/community/tests/integration_tests/llms/test_volcengine_maas.py

@@ -3,8 +3,35 @@
 from typing import Generator
 
 from langchain_core.outputs import LLMResult
+from langchain_core.pydantic_v1 import SecretStr
+from pytest import CaptureFixture
 
-from langchain_community.llms.volcengine_maas import VolcEngineMaasLLM
+from langchain_community.llms.volcengine_maas import (
+    VolcEngineMaasBase,
+    VolcEngineMaasLLM,
+)
+
+
+def test_api_key_is_string() -> None:
+    llm = VolcEngineMaasBase(
+        volc_engine_maas_ak="secret-volc-ak",
+        volc_engine_maas_sk="secret-volc-sk",
+    )
+    assert isinstance(llm.volc_engine_maas_ak, SecretStr)
+    assert isinstance(llm.volc_engine_maas_sk, SecretStr)
+
+
+def test_api_key_masked_when_passed_via_constructor(
+    capsys: CaptureFixture,
+) -> None:
+    llm = VolcEngineMaasBase(
+        volc_engine_maas_ak="secret-volc-ak",
+        volc_engine_maas_sk="secret-volc-sk",
+    )
+    print(llm.volc_engine_maas_ak, end="")
+    captured = capsys.readouterr()
+
+    assert captured.out == "**********"
 
 
 def test_default_call() -> None: