Web Application.

// 受注処理 API — 在庫・決済・通知を1トランザクションで
export const POST = async (req: Request) => {
  const body = await req.json()
  const result = await db.$transaction(async (tx) => {
    const stock = await tx.stock.lock(body.sku)
    if (stock.qty < body.qty) throw new OutOfStock()
    await stripe.charges.create({ amount: body.total })
    return tx.order.create({ data: body })
  })
  await notify(result.id, "order.created")
  return Response.json({ id: result.id }, { status: 201 })
}