Upload does not work for string feed.content (TypeError [ERR_INVALID_ARG_TYPE]: The "list" argument must be an instance of Array. Received type string ('<?xml version="1.0" enco...))

[andrii33]

Following the instruction https://www.npmjs.com/package/amazon-sp-api#encrypt-and-upload-feeds
There is an option to upload feed data as a string.
For example:

let feed = {
  content:`<?xml version="1.0" encoding="utf-8"?>
    <AmazonEnvelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="amzn-envelope.xsd">
      <Header>
        <DocumentVersion>1.02</DocumentVersion>
        <MerchantIdentifier>YOUR_MERCHANT_IDENTIFIER</MerchantIdentifier>
      </Header>
      <MessageType>Inventory</MessageType>
      <Message>
        <MessageID>1</MessageID>
        <Inventory>
          <SKU>YOUR_SKU</SKU>
          <Quantity>10</Quantity>
        </Inventory>
      </Message>
    </AmazonEnvelope>`,
  contentType:'text/xml; charset=utf-8'
}
const feedUploadDetails = {
      feedDocumentId: '3d4e42b5-1d6e-44e8-a89c-2abfca0625bb',
      url: 'https://d34o8swod1owfl.cloudfront.net/Feed_101__POST_PRODUCT_DATA_.xml'
}
let res = await sellingPartner.upload(feed_upload_details, feed);

The error is thrown in the case

TypeError [ERR_INVALID_ARG_TYPE]: The "list" argument must be an instance of Array. Received type string ('<?xml version="1.0" enco...)

Looks like on the line (https://github.com/amz-tools/amazon-sp-api/blob/main/lib/SellingPartner.js#L690) we need to have
something like:
content_buffer = Buffer.concat([Buffer.from(feed_content)]);
instead of
content_buffer = Buffer.concat(feed_content);

[amz-tools]

@andrii33 Thanks for noticing, we just published a fix.