guardia-messenger/node_modules/@web3-storage/multipart-parser/test/test.spec.js

import test from 'tape'
import { ReadableStream } from 'web-streams-polyfill/ponyfill/es2018'
import { iterateMultipart } from '../src/index.js'

const boundary = 'some random boundary'

test('can parse multipart from readable stream', async (t) => {
  const testPayload = multipartPayload(expectedParts, boundary)

  const files = []
  for await (const filePart of iterateMultipart(stream(testPayload, 3), boundary)) {
    files.push(filePart)
  }

  t.ok(files.length)
  t.end()
})

function multipartPayload (parts, boundary) {
  boundary = '\r\n--' + boundary
  return boundary + '\r\n' + parts.map((part) => {
    let contentDisposition = `Content-Disposition: form-data; name="${part.name}"`
    if (part.filename) {
      contentDisposition += `; filename="${part.filename}"`
    }

    let contentType = ''
    if (part.contentType) {
      contentType = `\r\nContent-Type: ${part.contentType}`
    }

    return contentDisposition + contentType + '\r\n\r\n' + part.data
  }).join(boundary + '\r\n') + boundary + '--'
}

const expectedParts = [
  { name: 'a', data: 'form value a' },
  { name: 'b', data: 'file value b', filename: 'b.txt' },
  { name: 'c', data: 'file value c\r\nhas\r\nsome new \r\n lines', filename: 'c.txt', contentType: 'text/plain' }
]

function stream (payload, size) {
  let pos = 0
  return new ReadableStream({
    type: 'bytes',
    pull: (controller) => {
      let end = pos + size
      if (end > payload.length) {
        end = payload.length
      }

      controller.enqueue(stringToArray(payload.slice(pos, end)))

      if (end === payload.length) {
        controller.close()
      }

      pos = end
    }
  })
}

function stringToArray (s) {
  return Uint8Array.from(s, (c) => c.charCodeAt(0))
}