// create a BlobReader to read with a ZipReader the zip from a Blob object
const reader = new zip.ZipReader(new zip.BlobReader(blob));

// get all entries from the zip
const entries = await reader.getEntries();
if (entries.length) {

  // get first entry content as text by using a TextWriter
  const text = await entries[0].getData(
    // writer
    new zip.TextWriter(),
    // options
    {
      onprogress: (index, max) => {
        // onprogress callback
      }
    }
  );
  // text contains the entry data as a String
  console.log(text);
}

// close the ZipReader
await reader.close();