Refactor: use SecretStr for GPTRouter chat-model (#15101)

libs/community/tests/integration_tests/chat_models/test_gpt_router.py

@@ -7,11 +7,34 @@ from langchain_core.callbacks import (
 )
 from langchain_core.messages import AIMessage, BaseMessage, HumanMessage
 from langchain_core.outputs import ChatGeneration, LLMResult
+from langchain_core.pydantic_v1 import SecretStr
+from pytest import CaptureFixture
 
 from langchain_community.chat_models.gpt_router import GPTRouter, GPTRouterModel
 from tests.unit_tests.callbacks.fake_callback_handler import FakeCallbackHandler
 
 
+def test_api_key_is_string() -> None:
+    gpt_router = GPTRouter(
+        gpt_router_api_base="https://example.com",
+        gpt_router_api_key="secret-api-key",
+    )
+    assert isinstance(gpt_router.gpt_router_api_key, SecretStr)
+
+
+def test_api_key_masked_when_passed_via_constructor(
+    capsys: CaptureFixture,
+) -> None:
+    gpt_router = GPTRouter(
+        gpt_router_api_base="https://example.com",
+        gpt_router_api_key="secret-api-key",
+    )
+    print(gpt_router.gpt_router_api_key, end="")
+    captured = capsys.readouterr()
+
+    assert captured.out == "**********"
+
+
 def test_gpt_router_call() -> None:
     """Test valid call to GPTRouter."""
     anthropic_claude = GPTRouterModel(