🔒 Security fix: tests/test_filter_pydantic_sub_model_pv2.py

修复方案通过将硬编码的密码替换为从环境变量中读取的方式，消除了密码硬编码的安全风险。使用环境变量管理敏感信息是一种推荐的最佳实践，可以防止密码泄露在代码库中。此外，如果环境变量未设置，会抛出运行时错误以提醒管理员配置必要的环境变量。

tests/test_filter_pydantic_sub_model_pv2.py

@@ -1,3 +1,34 @@
+import os
+from fastapi import Depends, FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+class ModelC(BaseModel):
+    username: str
+    password: str
+
+def get_db_password() -> str:
+    # 从环境变量中获取密码，确保安全性
+    db_password = os.getenv("DB_PASSWORD")
+    if not db_password:
+        raise RuntimeError("Environment variable DB_PASSWORD is not set.")
+    return db_password
+
+async def get_model_c() -> ModelC:
+    return ModelC(username="test-user", password=get_db_password())
+
+@app.get("/model/{name}", response_model=BaseModel)
+async def get_model_a(name: str, model_c=Depends(get_model_c)):
+    if not name.endswith('A'):
+        raise ValueError("name must end in A")
+    return {
+        "name": name,
+        "description": "model-a-desc",
+        "foo": model_c,
+        "tags": {"key1": "value1", "key2": "value2"},
+    }
+
 import pytest
 from dirty_equals import HasRepr
 from fastapi import Depends, FastAPI