✅ Add tests for validation errors in response

tests/test_serialize_response.py

@@ -0,0 +1,51 @@
+from typing import List
+
+import pytest
+from fastapi import FastAPI
+from pydantic import BaseModel, ValidationError
+from starlette.testclient import TestClient
+
+app = FastAPI()
+
+
+class Item(BaseModel):
+    name: str
+    price: float = None
+    owner_ids: List[int] = None
+
+
+@app.get("/items/invalid", response_model=Item)
+def get_invalid():
+    return {"name": "invalid", "price": "foo"}
+
+
+@app.get("/items/innerinvalid", response_model=Item)
+def get_innerinvalid():
+    return {"name": "double invalid", "price": "foo", "owner_ids": ["foo", "bar"]}
+
+
+@app.get("/items/invalidlist", response_model=List[Item])
+def get_invalidlist():
+    return [
+        {"name": "foo"},
+        {"name": "bar", "price": "bar"},
+        {"name": "baz", "price": "baz"},
+    ]
+
+
+client = TestClient(app)
+
+
+def test_invalid():
+    with pytest.raises(ValidationError):
+        client.get("/items/invalid")
+
+
+def test_double_invalid():
+    with pytest.raises(ValidationError):
+        client.get("/items/innerinvalid")
+
+
+def test_invalid_list():
+    with pytest.raises(ValidationError):
+        client.get("/items/invalidlist")