Reading XLSX from Stream - soares-marcio/js-xlsx GitHub Wiki
Reading XLSX from Stream
If you're trying to read from a Stream object, rather than a file, XLSX.read() or XLSX.readSync() won't work directly on streams, and will throw an error. However, you can easily use Buffers to work around that:
var filestream = getExcel().createReadStream(); // a readable stream
var buffers = [];
file.on('data', function(data) {
buffers.push(data);
});
file.on('end', function() {
var buffer = Buffer.concat(buffers);
var workbook = XLSX.read(buffer); // works
});