Issue when reading a zip file in Thunderbird

[bluesky335]

I am writing a Thunderbird extension and encountered an error when reading a zip file attachment in the background page.
The error message says ‘File format is not recognized’, but it works fine in Chrome.

Thunder Bird version: 102.11.2

[gildas-lormeau]

That probably means the JS runtime does not support generators. A way to fix this issue would be to compile zip.js with babel. The build script already exists, see https://github.com/gildas-lormeau/zip.js/blob/master/rollup-es5.config.js. You should just have to clone the project, run the npm install commands (cf. the top comment in rollup-es5.config.js) and npx rollup -c rollup-es5.config.js in order to build the files in the dist folder and the index.cjs file.

[bluesky335]

You can download demo code here

This is the code. You can find it at "/background/attachment-tool.js"

The document of browser.messageDisplay and browser.messages API
messageDisplay — WebExtension API Documentation for Thunderbird BetaManifest v2 documentation
messages — WebExtension API Documentation for Thunderbird BetaManifest v2 documentation

/**
 * 
 * @param {message from DisplayScripts} message 
 * @param {sender} sender 
 * @returns 
 */
export default async function checkAttachment(message, sender) {
  // get current displayed message's info
  const messageHeader = await browser.messageDisplay.getDisplayedMessage(sender.tab.id);
  // get attachment info list of this mesage
  const attachmentList = await browser.messages.listAttachments(messageHeader.id)
  if (attachmentList.length === 0) {
    console.log("no attachment");
    return
  }
  // get attachment File object 
  let attachmentFile = await browser.messages.getAttachmentFile(messageHeader.id, attachmentList[0].partName)

  const zipFileReader = new zip.BlobReader(attachmentFile);
  const zipReader = new zip.ZipReader(zipFileReader);
  const entries = await zipReader.getEntries();
  console.log("check-attachment", attachmentList, entries);
}

[gildas-lormeau]

I tried your demo in Thunderbird/102.12.0. It works fine for me, I attached the zip file of your extension in a (draft) mail and I don't see any errors when displaying the mail in Thunderbird. The following log is displayed in the background page of the extension:

check-attachment Array [ {…} ] Array(17) [ {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, … ] attachment-tool.js:17:11

[bluesky335]

I tested the zip file of extension demo too, it works fine. But maybe you should try with a file that is larger than 1MB.
There is the file which I used.

• Two images of Genshin Impact: genshin-images.zip
• Two Chromium license file: LICENSES.chromium.zip

[gildas-lormeau]

Thank you, I was able to reproduce the issue. I've just published the version 2.7.17 which should fix it. BTW, you don't need to use the ES5 version.