Uploading output of ExcelJS to Azure Blob Storage in NodeJS

So I am using ExcelJS to create an Excel file. Currently I am saving the file to disk. The data I am adding to the file is coming in from an API call.

let options = {
  filename: 'pathtofile',
  useStyles: true,
  useSharedStrings: true
}

let workbook = new Excel.stream.xlsx.WorkbookWriter(options)
let sheet = workbook.addWorksheet('myWorksheet')

// add some data to the file

sheet.commit()
workbook.commit()

I would like to now change it so it uploads to Azure Blob Storage. ExcelJS allows the specification of a stream instead of a filename in which to commit to. So I've decided to use Memory Streams JS so now the options look like this.

let stream = new streams.WritableStream()

let options = {
  stream: stream,
  useStyles: true,
  useSharedStrings: true
}

From reading the Azure documentation, the two most suitable methods seems to be createBlockBlobFromStream() and createWriteStreamToBlockBlob() and they both appear to want a Readable Stream (correct me if I'm wrong). This is where I'm stuck as I have a Writable Stream from using ExcelJS but I need a Readable Stream for Azure Blob Storage. Obviously I can still write the file to disk; create a Readable Stream from the file; and then finally delete the file after uploading to Azure Blob Storage but that is a lot of overhead. Am I going about this in a really roundabout way?

via Kevin Lee