readableStream.pipeThrough(transform[, options])

• transform <Object>
  • readable <ReadableStream> ReadableStream，transform.writable 将会把从该 ReadableStream 接收到的可能被修改的数据推送到这里。
  • writable <WritableStream> 将写入此 ReadableStream 数据的 WritableStream。
• options <Object>
  • preventAbort <boolean> 当为 true 时，该 ReadableStream 中的错误不会导致 transform.writable 被中止。
  • preventCancel <boolean> 当设置为 true 时，目标 transform.writable 中的错误不会导致此 ReadableStream 被取消。
  • preventClose <boolean> 当为 true 时，关闭此 ReadableStream 不会导致 transform.writable 被关闭。
  • signal <AbortSignal> 允许使用 <AbortController> 取消数据传输。
• 返回：从 transform.readable 获取 <ReadableStream>。

将此 <ReadableStream> 连接到 transform 参数中提供的 <ReadableStream> 和 <WritableStream> 对，使得此 <ReadableStream> 的数据被写入 transform.writable，可能经过转换，然后推送到 transform.readable。一旦管道配置完成，将返回 transform.readable。

【Connects this <ReadableStream> to the pair of <ReadableStream> and <WritableStream> provided in the transform argument such that the data from this <ReadableStream> is written in to transform.writable, possibly transformed, then pushed to transform.readable. Once the pipeline is configured, transform.readable is returned.】

在管道操作进行时，会导致 readableStream.locked 为 true。

【Causes the readableStream.locked to be true while the pipe operation is active.】

import {
  ReadableStream,
  TransformStream,
} from 'node:stream/web';

const stream = new ReadableStream({
  start(controller) {
    controller.enqueue('a');
  },
});

const transform = new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  },
});

const transformedStream = stream.pipeThrough(transform);

for await (const chunk of transformedStream)
  console.log(chunk);
  // Prints: Aconst {
  ReadableStream,
  TransformStream,
} = require('node:stream/web');

const stream = new ReadableStream({
  start(controller) {
    controller.enqueue('a');
  },
});

const transform = new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  },
});

const transformedStream = stream.pipeThrough(transform);

(async () => {
  for await (const chunk of transformedStream)
    console.log(chunk);
    // Prints: A
})();拷贝