transformStream

transformStream<T, U>(stream, transform): ReadableStream<U>

Defined in: stream-utils.ts:246

Transform a ReadableStream by applying a function to each chunk.

This utility creates a new ReadableStream that applies a transformation function to each chunk from the source stream. The transform function can be synchronous or asynchronous, allowing for complex processing pipelines. Useful for modifying stream data types or content on-the-fly.

Type Parameters

T

T

U

U

Parameters

stream

ReadableStream<T>

Source ReadableStream to transform

transform

(chunk) => U | Promise<U>

Function to apply to each chunk (sync or async)

Returns

ReadableStream<U>

New ReadableStream emitting transformed chunks

Example

const textStream = fetchStream(); // ReadableStream<Uint8Array>
const uppercaseStream = transformStream(textStream, (chunk) => {
  const text = new TextDecoder().decode(chunk);
  return new TextEncoder().encode(text.toUpperCase());
});