SvelteKit inject Sentry meta tags

import type { HandleServerError, RequestEvent } from '@sveltejs/kit';
import * as SentryNode from '@sentry/node';
import type { Handle } from '@sveltejs/kit';
import '@sentry/tracing';
import type { Transaction } from '@sentry/types';
import {
  baggageHeaderToDynamicSamplingContext,
  dynamicSamplingContextToSentryBaggageHeader
} from '@sentry/utils';
import parse from 'node-html-parser';
import { sequence } from '@sveltejs/kit/hooks';
import { RewriteFrames } from '@sentry/integrations';
console.log('Initting Sentry on SERVER!');

SentryNode.init({
  dsn: 'https://75ab9da4161c45f89b679ee9629a37eb@o4504389074223104.ingest.sentry.io/4504389080514560',
  tracesSampleRate: 1.0,
  debug: true,
  integrations: [new SentryNode.Integrations.Http(), new RewriteFrames()]
});
SentryNode.setTag('svelteKit', 'server');

export const handleError = (({ error, event }) => {
  SentryNode.captureException(error, { contexts: { sveltekit: { event } } });

  console.log('>>>', typeof error, error, event);
  console.log('msg:', error.message);

  return { message: error.message };
}) satisfies HandleServerError;

const sentryHandle = (async (props) => {
  const { event, resolve } = props;
  console.log('--------------SERVER-HANDLE-START--------------------');

  console.log(event.request);
  const transaction = createTransaction(event);

  const response = await resolve(event, {
    transformPageChunk: ({ html }) => {
      console.log('>>> this is parse', parse);

      if (!parse || typeof parse !== 'function') {
        return html;
      }

      const document = parse(html);
      const head = document.querySelector('head');
      if (!head) {
        return html;
      }

      head?.set_content(
        head?.innerHTML +
          `<meta name="sentry-trace" content="${transaction?.toTraceparent()}"/>` +
          `<meta name="baggage" content="${dynamicSamplingContextToSentryBaggageHeader(
            transaction?.getDynamicSamplingContext() || {}
          )}"/>`
      );

      return document.toString();
    }
  });

  const eventType = getServerEventType(event);
  if (eventType === 'page') {
    const html = response.body;
    console.log(html);
  }

  finishTransaction(transaction, response);
  console.log('--------------SERVER-HANDLE-STOP--------------------');

  return response;
}) satisfies Handle;

export const handle = sequence(sentryHandle);

function createTransaction(event: RequestEvent): Transaction | undefined {
  const transaction = SentryNode.startTransaction({
    name: `${event.request.method} ${event.route.id}`,
    op: 'http.server',
    description: `${event.request.method} ${event.route.id}`
  });

  if (!transaction) {
    return undefined;
  }

  transaction.traceId =
    event.request.headers.get('sentry-trace')?.split('-')[0] || transaction.traceId;
  transaction.sampled =
    event.request.headers.get('sentry-trace')?.split('-')[2] === '1' || transaction.sampled;

  transaction.setMetadata({
    ...transaction.metadata,
    dynamicSamplingContext: baggageHeaderToDynamicSamplingContext(
      event.request.headers.get('baggage')
    ),
    source: 'route'
  });

  SentryNode.getCurrentHub().getScope()?.setSpan(transaction);
  addTags(event, transaction);

  return transaction;
}

function finishTransaction(transaction: Transaction | undefined, response: Response) {
  transaction?.setHttpStatus(response.status);
  transaction?.finish();
}

function addTags(event: RequestEvent | undefined, transaction: Transaction | undefined) {
  if (!transaction || !event) {
    return;
  }

  const serverEventType = getServerEventType(event);

  transaction.tags = {
    ...transaction.tags,
    ...(serverEventType === 'data' && { data_request: true }),
    ...(serverEventType === 'page' && { page_request: true }),
    ...(serverEventType === 'api' && { api_request: true })
  };
}

type ServerEventType = 'data' | 'api' | 'page';

function getServerEventType(event: RequestEvent): ServerEventType {
  if (event.isDataRequest === true) {
    return 'data';
  }

  if (event.route.id && event.route.id.includes('/api/')) {
    return 'api';
  }

  return 'page';
}