Tauri wrtie file from ReadableStream

write-file-from-stream.ts

import { writeFile, type WriteFileOptions } from '@tauri-apps/plugin-fs'

export async function writeFileFromStream(
  path: string | URL,
  stream: ReadableStream<Uint8Array>,
  options?: WriteFileOptions & { chunkSize?: number }
) {
  const chunkSize = options?.chunkSize ?? 1024 * 1024 // 1MB in bytes
  const reader = stream.getReader()

  let chunks: Uint8Array[] = []
  let bytesRead = 0

  // eslint-disable-next-line no-constant-condition
  while (true) {
    const { done, value } = await reader.read()
    if (done) break

    chunks.push(value)
    bytesRead += value.length

    if (bytesRead >= chunkSize) {
      const chunk = new Uint8Array(bytesRead)
      let offset = 0
      for (const chunkValue of chunks) {
        chunk.set(chunkValue, offset)
        offset += chunkValue.length
      }

      await writeFile(path, chunk, {
        ...options,
        append: true
      })
      chunks = []
      bytesRead = 0
    }
  }

  if (bytesRead > 0) {
    const chunk = new Uint8Array(bytesRead)
    let offset = 0
    for (const chunkValue of chunks) {
      chunk.set(chunkValue, offset)
      offset += chunkValue.length
    }
    await writeFile(path, chunk, {
      ...options,
      append: true
    })
  }
}