fix(backends): serialize timedelta values in JSON responses

aiohttp_admin/backends/abc.py

@@ -3,7 +3,7 @@
 import sys
 from abc import ABC, abstractmethod
 from collections.abc import Sequence
-from datetime import date, datetime, time
+from datetime import date, datetime, time, timedelta
 from enum import Enum
 from functools import cached_property, partial
 from types import MappingProxyType
@@ -41,7 +41,7 @@
 
 class Encoder(json.JSONEncoder):
     def default(self, o: object) -> Any:
-        if isinstance(o, (date, time)):
+        if isinstance(o, (date, time, timedelta)):
             return str(o)
         if isinstance(o, Enum):
             return o.value

tests/test_backends_sqlalchemy.py

@@ -1,6 +1,6 @@
 import json
 from collections.abc import Awaitable, Callable
-from datetime import date, datetime
+from datetime import date, datetime, timedelta
 from typing import Optional, Union
 
 import pytest
@@ -139,6 +139,43 @@ class TestModel(base):  # type: ignore[misc,valid-type]
         assert await resp.json() == {"data": {"id": "2", "data": {"id": 2, "binary": "\x01�\x02"}}}
 
 
+async def test_interval(
+    base: DeclarativeBase, aiohttp_client: Callable[[web.Application], Awaitable[_Client]],
+    login: _Login
+) -> None:
+    class TestModel(base):  # type: ignore[misc,valid-type]
+        __tablename__ = "test"
+        id: Mapped[int] = mapped_column(primary_key=True)
+        duration: Mapped[timedelta] = mapped_column(sa.Interval())
+
+    app = web.Application()
+    engine = create_async_engine("sqlite+aiosqlite:///:memory:")
+    db = async_sessionmaker(engine, expire_on_commit=False)
+    async with engine.begin() as conn:
+        await conn.run_sync(base.metadata.create_all)
+    async with db.begin() as sess:
+        sess.add(TestModel(duration=timedelta(hours=2, minutes=30)))
+
+    schema: aiohttp_admin.Schema = {
+        "security": {
+            "check_credentials": check_credentials,
+            "secure": False
+        },
+        "resources": ({"model": SAResource(engine, TestModel)},)
+    }
+    app[admin] = aiohttp_admin.setup(app, schema)
+
+    admin_client = await aiohttp_client(app)
+    assert admin_client.app
+    h = await login(admin_client)
+
+    # timedelta values must serialize (Encoder previously raised TypeError -> 500).
+    url = app[admin].router["test_get_one"].url_for()
+    async with admin_client.get(url, params={"id": 1}, headers=h) as resp:
+        assert resp.status == 200
+        assert await resp.json() == {"data": {"id": "1", "data": {"id": 1, "duration": "2:30:00"}}}
+
+
 def test_fk(base: type[DeclarativeBase], mock_engine: AsyncEngine) -> None:
     class TestModel(base):  # type: ignore[misc,valid-type]
         __tablename__ = "dummy"