JSZip library, checking if zipfile is encrypted or not

Question

Good day, I was wondering how can i check if the zip file is encrypted or not using JSZip library. I currently try to do a loadAsync function then if it goes to .catch() I always assume the reason for it is cause it is encrypted. I know there should be a better way to do this so I tried to check for the library itself then found entries having an isEncrypted() function being called. I just do not know how to access those entries. anyone knows how?

if (hasZipFileFlag === true) {
var jszip = new JSZip();
try {
    await jszip.loadAsync(testZip).then(function(res) {
      UtilLogClass.logFunc('ZIP READ SUCCESSFULLY', res);
    }).catch((err) => {
      UtilLogClass.logFunc('jszip loadAsync then() ERROR', err);
      zipFileHasPassFlag = true;
    });
  } catch (err) {
    UtilLogClass.logFunc('ZIP READ ERROR', err);
  }
}

※testZip is already a DOM object having a type of "application/x-zip-compressed" and I already have a way to determine if it is a zip file or not.

Answer 1

From the JSZip limitations docs, it looks like it's not possible:

Not all features of zip files are supported. Classic zip files will work but encrypted zip, multi-volume, etc are not supported and the loadAsync() method will return a failed promise.

Edit (per comments):

You could refactor your code into something like this:

if (hasZipFileFlag === true) {
  var jszip = new JSZip();
  try {
    const res = await jszip.loadAsync(testZip);
    UtilLogClass.logFunc("ZIP READ SUCCESSFULLY", res);
  } catch (err) {
    // if(err === "encrypted error from JSZip") { ... } 
    zipFileHasPassFlag = true;
    UtilLogClass.logFunc("ZIP READ ERROR", err);
  }
}

Any error thrown by the loadAync(...) method will be caught by the catch block.