Unknown extension:

[kriiv]

I've deployed this repo with the standard code, no modifications. When triggering the worker via an email route I get the following:

{
  "outcome": "exception",
  "scriptName": "dmarc-email-worker",
  "diagnosticsChannelEvents": [],
  "exceptions": [
    {
      "name": "Error",
      "message": "unknown extension: ",
      "timestamp": 1709945220800
    }
  ],
  "logs": [],
  "eventTimestamp": 1709945220127,
  "event": {
    "rawSize": 6515,
    "rcptTo": "<redacted>",
    "mailFrom": "<redacted>"
  },
  "id": 1
}

Any thoughts on how I can get this to work properly? The file is being stored into R2 but nothing happens after that. Strange as I'm using the default code and instructions form the repo.

[dattaproffs]

This is because outlook for example uses the mime type "application/x-gzip" and if you look in the mime-db repo there is no extension for that mime type. The same goes for other vendors like google and yahoo. they also use some x- variant of the mime type.

You could either do a PR to mime-db and add the ones you find are missing or just do a quick and dirty "fix" and look at the file extension.

const filenameParts = attachment.filename.split('.');
const fileExtension = filenameParts[filenameParts.length - 1];
if(extension === '')
    extension = fileExtension;

[kriiv]

Perfect! That worked. Thanks a lot.

[kriiv]

For reference, I edited index.ts with the following:

async function getDMARCReportXML(attachment: Attachment) {
  let xml;
  const xmlParser = new XMLParser();
  let extension = mimeDb[attachment.mimeType]?.extensions?.[0] || '';

  if (extension === '') {
    const filenameParts = attachment.filename.split('.');
    extension = filenameParts[filenameParts.length - 1];
  }

  switch (extension) {
    case 'gz':
      xml = pako.inflate(new TextEncoder().encode(attachment.content as string), { to: 'string' });
      break;

    case 'zip':
      xml = await getXMLFromZip(attachment.content);
      break;

    case 'xml':
      xml = await new Response(attachment.content).text();
      break;

    default:
      throw new Error(`unknown extension: ${extension}`);
  }

  return await xmlParser.parse(xml);
}