CD
Cloudflare Developers•4w ago
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How to test an email Worker locally?

I am trying to make an email Worker, I am using an example, but I have no idea how to test it. index.js: 
const PostalMime = require("postal-mime");

async function streamToArrayBuffer(stream, streamSize) {
  let result = new Uint8Array(streamSize);
  let bytesRead = 0;
  const reader = stream.getReader();
  while (true) {
    const { done, value } = await reader.read();
    if (done) {
      break;
    }
    result.set(value, bytesRead);
    bytesRead += value.length;
  }
  return result;
}

export default {
  async email(event, env, ctx) {
    const rawEmail = await streamToArrayBuffer(event.raw, event.rawSize);
    const parser = new PostalMime.default();
    const parsedEmail = await parser.parse(rawEmail);
    console.log("Mail subject: ", parsedEmail.subject);
    console.log("Mail message ID", parsedEmail.messageId);
    console.log("HTML version of Email: ", parsedEmail.html);
    console.log("Text version of Email: ", parsedEmail.text);
    if (parsedEmail.attachments.length == 0) {
      console.log("No attachments");
    } else {
      parsedEmail.attachments.forEach((att) => {
        console.log("Attachment: ", att.filename);
        console.log("Attachment disposition: ", att.disposition);
        console.log("Attachment mime type: ", att.mimeType);
        console.log("Attachment size: ", att.content.byteLength);
      });
    }
  },
};
const PostalMime = require("postal-mime");

async function streamToArrayBuffer(stream, streamSize) {
  let result = new Uint8Array(streamSize);
  let bytesRead = 0;
  const reader = stream.getReader();
  while (true) {
    const { done, value } = await reader.read();
    if (done) {
      break;
    }
    result.set(value, bytesRead);
    bytesRead += value.length;
  }
  return result;
}

export default {
  async email(event, env, ctx) {
    const rawEmail = await streamToArrayBuffer(event.raw, event.rawSize);
    const parser = new PostalMime.default();
    const parsedEmail = await parser.parse(rawEmail);
    console.log("Mail subject: ", parsedEmail.subject);
    console.log("Mail message ID", parsedEmail.messageId);
    console.log("HTML version of Email: ", parsedEmail.html);
    console.log("Text version of Email: ", parsedEmail.text);
    if (parsedEmail.attachments.length == 0) {
      console.log("No attachments");
    } else {
      parsedEmail.attachments.forEach((att) => {
        console.log("Attachment: ", att.filename);
        console.log("Attachment disposition: ", att.disposition);
        console.log("Attachment mime type: ", att.mimeType);
        console.log("Attachment size: ", att.content.byteLength);
      });
    }
  },
};
1 Reply
DaniFoldi
DaniFoldi•4w ago
unfortunately local dev is not supported currently :/ you will have to deploy it to be able to receive emails what you can try to do is capture the event from a real email, and then reconstruct it locally* for testing it with a wrapper, or vitest *it won't be exactly identical because classes, but close enough for a postal-mime parse

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