import { Readable } from 'node:stream';
import type { ReadableStream as NodeReadableStream } from 'node:stream/web';
import { FetchError } from './errors.js';
import { isObject } from './type-guards.js';
type CompatibleReadableStream = ReadableStream<Uint8Array> &
NodeReadableStream<Uint8Array>;
function isReadableStreamLike(
value: unknown
): value is CompatibleReadableStream {
if (!isObject(value)) return false;
return (
typeof value['getReader'] === 'function' &&
typeof value['cancel'] === 'function' &&
typeof value['tee'] === 'function' &&
typeof value['locked'] === 'boolean'
);
}
function assertReadableStreamLike(
stream: unknown,
url: string,
stage: string
): asserts stream is CompatibleReadableStream {
if (isReadableStreamLike(stream)) return;
throw new FetchError('Invalid response stream', url, 500, {
reason: 'invalid_stream',
stage,
});
}
export function toNodeReadableStream(
stream: ReadableStream<Uint8Array>,
url: string,
stage: string
): NodeReadableStream<Uint8Array> {
assertReadableStreamLike(stream, url, stage);
return stream;
}
export function toWebReadableStream(
stream: Readable,
url: string,
stage: string
): ReadableStream<Uint8Array> {
const converted: unknown = Readable.toWeb(stream);
assertReadableStreamLike(converted, url, stage);
return converted;
}
