Function readTextWithByteLimit

src/webview/fetch-utils.ts:6–37

(response: Response, maxBytes: number, tooLargeMessage: string)

 *--------------------------------------------------------------------------------------------*/

export async function readTextWithByteLimit(response: Response, maxBytes: number, tooLargeMessage: string): Promise<string> {
  const declared = Number(response.headers.get('content-length'));
  if (Number.isFinite(declared) && declared > maxBytes) {
    throw new Error(tooLargeMessage);
  }

  if (!response.body) {
    const text = await response.text();
    if (new TextEncoder().encode(text).byteLength > maxBytes) {
      throw new Error(tooLargeMessage);
    }
    return text;
  }

  const reader = response.body.getReader();
  const decoder = new TextDecoder();
  let bytes = 0;
  let text = '';

  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    bytes += value.byteLength;
    if (bytes > maxBytes) {
      await reader.cancel();
      throw new Error(tooLargeMessage);
    }
    text += decoder.decode(value, { stream: true });
  }

  return text + decoder.decode();
}