payment-processing-test/tests/integration/test_outbox.py

import asyncio
from collections.abc import AsyncIterator
from typing import Any, cast

import pytest
from faststream.rabbit import RabbitBroker
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker

from app.models import OutboxEvent
from app.outbox import OutboxPublisher
from app.payments import create_payment
from app.schemas import PaymentCreate


class RecordingBroker:
    def __init__(self, error: Exception | None = None) -> None:
        self.error = error
        self.calls: list[tuple[dict[str, Any], dict[str, Any]]] = []

    async def publish(self, payload: dict[str, Any], **kwargs: Any) -> None:
        self.calls.append((payload, kwargs))
        if self.error is not None:
            raise self.error


class BlockingBroker(RecordingBroker):
    def __init__(self) -> None:
        super().__init__()
        self.started = asyncio.Event()
        self.release = asyncio.Event()

    async def publish(self, payload: dict[str, Any], **kwargs: Any) -> None:
        self.calls.append((payload, kwargs))
        self.started.set()
        await self.release.wait()


@pytest.fixture
async def pending_event(
    database: async_sessionmaker[AsyncSession],
) -> AsyncIterator[OutboxEvent]:
    async with database() as session:
        payment = await create_payment(
            session,
            PaymentCreate(
                amount="10.00",
                currency="USD",
                description="Outbox test",
                webhook_url="https://example.com/hook",
            ),
            "outbox-key",
        )
        event = await session.scalar(
            select(OutboxEvent).where(OutboxEvent.aggregate_id == payment.id)
        )
        assert event is not None
        yield event


def make_publisher(
    database: async_sessionmaker[AsyncSession],
    broker: RecordingBroker,
) -> OutboxPublisher:
    return OutboxPublisher(
        database,
        cast(RabbitBroker, broker),
        batch_size=10,
        poll_interval=0.01,
        publish_timeout=1,
    )


async def test_successful_publish_marks_event(
    database: async_sessionmaker[AsyncSession],
    pending_event: OutboxEvent,
) -> None:
    broker = RecordingBroker()

    published = await make_publisher(database, broker).publish_batch()

    async with database() as session:
        event = await session.get(OutboxEvent, pending_event.id)
        assert event is not None
        assert event.published_at is not None
        assert event.attempts == 1
        assert event.last_error is None
    assert published == 1
    assert broker.calls[0][0] == {"payment_id": str(pending_event.aggregate_id)}
    assert broker.calls[0][1]["queue"] == "payments.new"
    assert broker.calls[0][1]["persist"] is True


async def test_failed_publish_remains_pending(
    database: async_sessionmaker[AsyncSession],
    pending_event: OutboxEvent,
) -> None:
    broker = RecordingBroker(RuntimeError("rabbit unavailable"))

    published = await make_publisher(database, broker).publish_batch()

    async with database() as session:
        event = await session.get(OutboxEvent, pending_event.id)
        assert event is not None
        assert event.published_at is None
        assert event.attempts == 1
        assert event.last_error == "rabbit unavailable"
    assert published == 0


async def test_failed_event_is_published_on_next_iteration(
    database: async_sessionmaker[AsyncSession],
    pending_event: OutboxEvent,
) -> None:
    broker = RecordingBroker(RuntimeError("rabbit unavailable"))
    publisher = make_publisher(database, broker)
    assert await publisher.publish_batch() == 0

    broker.error = None
    assert await publisher.publish_batch() == 1

    async with database() as session:
        event = await session.get(OutboxEvent, pending_event.id)
        assert event is not None
        assert event.published_at is not None
        assert event.attempts == 2
        assert event.last_error is None


async def test_concurrent_publishers_publish_event_once(
    database: async_sessionmaker[AsyncSession],
    pending_event: OutboxEvent,
) -> None:
    blocking_broker = BlockingBroker()
    other_broker = RecordingBroker()
    first = asyncio.create_task(make_publisher(database, blocking_broker).publish_batch())
    await asyncio.wait_for(blocking_broker.started.wait(), timeout=1)

    second_result = await make_publisher(database, other_broker).publish_batch()
    blocking_broker.release.set()
    first_result = await asyncio.wait_for(first, timeout=1)

    assert first_result == 1
    assert second_result == 0
    assert len(blocking_broker.calls) == 1
    assert other_broker.calls == []
    async with database() as session:
        event = await session.get(OutboxEvent, pending_event.id)
        assert event is not None
        assert event.published_at is not None


async def test_stop_event_prevents_publishing_selected_events(
    database: async_sessionmaker[AsyncSession],
    pending_event: OutboxEvent,
) -> None:
    broker = RecordingBroker()
    stop_event = asyncio.Event()
    stop_event.set()

    published = await make_publisher(database, broker).publish_batch(stop_event)

    assert published == 0
    assert broker.calls == []
    async with database() as session:
        event = await session.get(OutboxEvent, pending_event.id)
        assert event is not None
        assert event.published_at is None