How to unzip a file using JavaScript that is in base64 format

General
1

I have base64 string that is a zip file. I need to extract the file the zip file and to do so I was trying to utilize a library noted in an answer here on Stack Overflow called fflate:

  attachmentsFlat.forEach(async (attachment) => {
  attachment = await emailStore.getAttachment(props.mailbox, attachment.email_id, attachment.id)
  if(attachment.file_name.split('.').pop() ==  'zip') {

    const decompressed = fflate.decompressSync(attachment.content_bytes);
    console.log(decompressed)
  }

However, this results in an error:

fflate.js?v=2017d673:285 Uncaught (in promise) TypeError: dat.subarray is not a function
at inflt (fflate.js?v=2017d673:285:21)
at inflateSync (fflate.js?v=2017d673:1103:10)
at Module.decompressSync (fflate.js?v=2017d673:1421:160)
at EmailFilesAssignment.vue:150:37

If this library does not work I am open to other libraries that can take base64 and unzip the files. I just cannot find many example of unzip files but more so zipping and using base64 is a special example I cannot find.

I also attempted to do this via JSZip but I am unsure how to get the files out asynchronously. I have tried the following:

attachmentsFlat.forEach(async (attachment) => {
  attachment = await emailStore.getAttachment(props.mailbox, attachment.email_id, attachment.id)
  if(attachment.file_name.split('.').pop() ==  'zip') {
    const zipFiles = await uncompressZipAttachment(attachment)
    console.log(zipFiles) // shows [] and 8 entries in console
    console.log(zipFiles[0]) //always returns undefined
  }
})
  const dataURLtoFile = (base64String: string, contentType: string | undefined, filename: string) => {
        let mime = contentType
        let bstr = atob(base64String) 
        let n = bstr.length
        let u8arr = new Uint8Array(n)
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new File([u8arr], filename, {type:mime});
}

  const uncompressZipAttachment = async (attachment : FileAttachment) : Promise<any> => {
    let files : File[] = []
    const decompressedZipFiles = await jsZip.loadAsync(dataURLtoFile(attachment.content_bytes, attachment.content_type, attachment.file_name))
    decompressedZipFiles.forEach(async (filename) => {
      let fileData = await decompressedZipFiles.files[filename].async("blob"); 
      files.push(new File([fileData], filename))
    })
    return files
  }