Serverless async-задачи: четыре способа поставить работу в очередь

export async function handler(event) {
  const { reportId } = JSON.parse(event.body || '{}');
  if (!reportId) return { statusCode: 400, body: JSON.stringify({ error: 'reportId required' }) };
  // Return immediately — job runs outside HTTP window
  const { instanceId: jobId } = await global.durable.startNew('generate-report', undefined, { reportId });
  return { statusCode: 202, body: JSON.stringify({ jobId }) };
}

import { createHmac, timingSafeEqual } from 'node:crypto';
export async function handler(event) {
  const body = event.body ?? '';
  const sig = event.headers['x-webhook-signature'] ?? '';
  const expected = createHmac('sha256', process.env.WEBHOOK_SECRET).update(body).digest('hex');
  if (!timingSafeEqual(Buffer.from(sig), Buffer.from(expected)))
    return { statusCode: 401, body: 'invalid signature' };
  const payload = JSON.parse(body);
  const isNew = await db.upsertEvent(payload.id, payload.type); // idempotency key
  if (!isNew) return { statusCode: 200, body: 'duplicate' };
  await global.durable.startNew('process-event', undefined, { eventId: payload.id, type: payload.type });
  return { statusCode: 200, body: 'accepted' };
}

export async function handler(event) {
  // event.trigger.type === 'schedule' when fired by a cronTrigger node
  // Cron minimum interval: 1 minute; fires within ~30s of scheduled time
  const since = process.env.LAST_CURSOR ?? new Date(Date.now() - 86_400_000).toISOString();
  const records = await source.fetchUpdatedSince(since);
  if (records.length === 0) return { synced: 0 };
  await destination.upsertBatch(records); // idempotent by record ID
  return { synced: records.length, cursor: records.at(-1)?.updatedAt };
}

export async function handler(event) {
  // Parent step output available as event.previousOutput
  const { batchId, items } = event.payload ?? {};
  // Fan-out: spawn one child pipeline per item
  const children = await Promise.all(
    items.map((item) =>
      global.durable.startNew('process-item', undefined, { batchId, itemId: item.id })
    )
  );
  return { batchId, spawned: children.length };
}