@defra-fish/pocl-job/src/transform/pocl-transform-stream.js

Post Office Counter Licence sales processor

import { Transaction } from './bindings/pocl/transaction/transaction.bindings.js'
import SaxStream from 'sax-stream'
import stream from 'stream'
import util from 'util'
import fs from 'fs'
const pipeline = util.promisify(stream.pipeline)

/**
 * Transform POCL XML into a JSON structure suitable for submitting to the Sales API.
 *
 * @param {string} xmlFilePath The path of the XML file to read from
 * @param {WritableStream} writableStream The writeable stream to consume the JSON data
 * @returns {Promise<void>}
 */
export const transform = async (xmlFilePath, ...writableStream) => {
  await pipeline([
    fs.createReadStream(xmlFilePath),
    SaxStream({ highWaterMark: 25, strict: true, trim: true, normalize: true, xmlns: false, tag: Transaction.element }),
    async function * (source) {
      for await (const data of source) {
        try {
          yield await Transaction.transform(data)
        } catch (e) {
          console.error('Error processing POCL transaction', e, data)
          throw e
        }
      }
    },
    ...writableStream
  ])
}