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- import {isReadableStream} from 'is-stream';
- import {asyncIterator} from '@sec-ant/readable-stream/ponyfill';
- export const getAsyncIterable = stream => {
- if (isReadableStream(stream, {checkOpen: false}) && nodeImports.on !== undefined) {
- return getStreamIterable(stream);
- }
- if (typeof stream?.[Symbol.asyncIterator] === 'function') {
- return stream;
- }
- // `ReadableStream[Symbol.asyncIterator]` support is missing in multiple browsers, so we ponyfill it
- if (toString.call(stream) === '[object ReadableStream]') {
- return asyncIterator.call(stream);
- }
- throw new TypeError('The first argument must be a Readable, a ReadableStream, or an async iterable.');
- };
- const {toString} = Object.prototype;
- // The default iterable for Node.js streams does not allow for multiple readers at once, so we re-implement it
- const getStreamIterable = async function * (stream) {
- const controller = new AbortController();
- const state = {};
- handleStreamEnd(stream, controller, state);
- try {
- for await (const [chunk] of nodeImports.on(stream, 'data', {signal: controller.signal})) {
- yield chunk;
- }
- } catch (error) {
- // Stream failure, for example due to `stream.destroy(error)`
- if (state.error !== undefined) {
- throw state.error;
- // `error` event directly emitted on stream
- } else if (!controller.signal.aborted) {
- throw error;
- // Otherwise, stream completed successfully
- }
- // The `finally` block also runs when the caller throws, for example due to the `maxBuffer` option
- } finally {
- stream.destroy();
- }
- };
- const handleStreamEnd = async (stream, controller, state) => {
- try {
- await nodeImports.finished(stream, {
- cleanup: true,
- readable: true,
- writable: false,
- error: false,
- });
- } catch (error) {
- state.error = error;
- } finally {
- controller.abort();
- }
- };
- // Loaded by the Node entrypoint, but not by the browser one.
- // This prevents using dynamic imports.
- export const nodeImports = {};
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