Merge PR #622: fix: retry critical Cashu storage writes

tests/unit/test_cashu_transaction_storage_retry.py

@@ -0,0 +1,91 @@
+from typing import Any
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from sqlalchemy.ext.asyncio import create_async_engine
+from sqlmodel import SQLModel, select
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.core import db
+
+
+@pytest.mark.asyncio
+async def test_cashu_transaction_storage_retries_then_succeeds() -> None:
+    store = AsyncMock(side_effect=[OSError("database locked"), True])
+    sleep = AsyncMock()
+
+    with (
+        patch("routstr.core.db.store_cashu_transaction", store),
+        patch("routstr.core.db.asyncio.sleep", sleep),
+    ):
+        stored = await db.store_cashu_transaction_with_retry(
+            token="cashuAretry",
+            amount=100,
+            unit="sat",
+        )
+
+    assert stored is True
+    assert store.await_count == 2
+    sleep.assert_awaited_once_with(0.25)
+
+
+@pytest.mark.asyncio
+async def test_cashu_transaction_retry_is_idempotent_after_ambiguous_commit() -> None:
+    engine = create_async_engine("sqlite+aiosqlite://")
+    async with engine.begin() as connection:
+        await connection.run_sync(SQLModel.metadata.create_all)
+
+    original_store = db.store_cashu_transaction
+    attempts = 0
+
+    async def ambiguous_store(**kwargs: Any) -> bool:
+        nonlocal attempts
+        attempts += 1
+        stored = await original_store(**kwargs)
+        if attempts == 1:
+            raise OSError("connection dropped after commit")
+        return stored
+
+    with (
+        patch.object(db, "engine", engine),
+        patch("routstr.core.db.store_cashu_transaction", ambiguous_store),
+        patch("routstr.core.db.asyncio.sleep", AsyncMock()),
+    ):
+        stored = await db.store_cashu_transaction_with_retry(
+            token="cashuAambiguous",
+            amount=100,
+            unit="sat",
+        )
+
+        async with AsyncSession(engine) as session:
+            result = await session.exec(select(db.CashuTransaction))
+            transactions = result.all()
+
+    assert stored is True
+    assert attempts == 2
+    assert len(transactions) == 1
+    await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_cashu_transaction_storage_raises_after_bounded_retries() -> None:
+    error = OSError("database unavailable")
+    store = AsyncMock(side_effect=error)
+    sleep = AsyncMock()
+
+    with (
+        patch("routstr.core.db.store_cashu_transaction", store),
+        patch("routstr.core.db.asyncio.sleep", sleep),
+        patch("routstr.core.db.logger.critical") as critical,
+    ):
+        with pytest.raises(OSError, match="database unavailable"):
+            await db.store_cashu_transaction_with_retry(
+                token="cashuAfail",
+                amount=100,
+                unit="sat",
+                max_attempts=3,
+            )
+
+    assert store.await_count == 3
+    assert [call.args[0] for call in sleep.await_args_list] == [0.25, 0.5]
+    critical.assert_called_once()