@webbridge-native/streams

WHATWG Streams API polyfill for React Native. Provides ReadableStream, WritableStream, and TransformStream implementations focused on HTTP response streaming.

Usage

import {
  WBReadableStream,
  WBWritableStream,
  WBTransformStream,
  CountQueuingStrategy,
  ByteLengthQueuingStrategy,
} from '@webbridge-native/streams';

ReadableStream

const stream = new WBReadableStream<string>({
  start(controller) {
    controller.enqueue('hello');
    controller.enqueue('world');
    controller.close();
  },
});

const reader = stream.getReader();
const { value, done } = await reader.read(); // { value: 'hello', done: false }

WritableStream

const stream = new WBWritableStream<string>({
  write(chunk) {
    console.log('Received:', chunk);
  },
});

const writer = stream.getWriter();
await writer.write('data');
await writer.close();

TransformStream

const uppercase = new WBTransformStream<string, string>({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  },
});

// Pipe through
const result = readable.pipeThrough(uppercase);

Queuing Strategies

// Count-based backpressure (1 per chunk)
const countStrategy = new CountQueuingStrategy({ highWaterMark: 10 });

// Byte-length backpressure
const byteStrategy = new ByteLengthQueuingStrategy({ highWaterMark: 65536 });

API

| Class | Description | |---|---| | WBReadableStream | Source of streaming data with reader, tee, pipeTo, pipeThrough | | WBWritableStream | Sink for streaming data with writer, close, abort | | WBTransformStream | Pairs readable + writable with a transformation function | | CountQueuingStrategy | Counts each chunk as size 1 | | ByteLengthQueuingStrategy | Uses byteLength for backpressure |

Notes

• No external dependencies
• Focused on practical HTTP streaming use cases
• Proper state machine (readable/writable/closed/errored)
• Backpressure via desiredSize and highWaterMark
• Error propagation through pipelines