Re: [whatwg/fetch] Add size limiter to `Body#formData` method (Issue #1592)

@wattroll, your approach is great but it does load everything in memory.

The following does essentially the same without draining the stream:

```ts 

export async function fetchMaxSizeProcessor(
  response: Resonse,
  maxBytes: number
) {
  if (!response.body) return response

  const contentLength = response.headers.get('content-length')
  if (contentLength) {
    const length = Number(contentLength)
    if (length > maxBytes) {
      const err = createError(502, 'Response too large', {
        response,
      })
      await response.body.cancel(err)
      throw err
    }
  }

  const newBody = response.body.pipeThrough(
    new ByteCounterTransformStream(maxBytes)
  )
  const newResponse = new Response(newBody, response)

  // Some props do not get copied by the Response constructor (e.g. url)
  for (const key in response) {
    const prop = key as keyof typeof response
    const value = response[prop]
    if (value !== newResponse[prop]) {
      Object.defineProperty(newResponse, prop, {
        value,
        writable: false,
        enumerable: true,
        configurable: true,
      })
    }
  }

  return newResponse
}
```

-- 
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/issues/1592#issuecomment-1866300231
You are receiving this because you are subscribed to this thread.

Message ID: <whatwg/fetch/issues/1592/1866300231@github.com>