@kawaz/fixed-chunk-stream

A lightweight TypeScript library that transforms streams into fixed-size chunks. This utility class extends TransformStream to provide efficient chunking of byte streams with configurable behavior for handling incomplete chunks.

Features

- Transform byte streams into fixed-size chunks
- TypeScript support with full type definitions
- Configurable handling of incomplete chunks at stream end
- Zero dependencies
- Works with Web Streams API

Installation

``bash


Using npm

npm install @kawaz/fixed-chunk-stream

Using yarn

yarn add @kawaz/fixed-chunk-stream

Using bun

bun add @kawaz/fixed-chunk-stream
`

Usage

$3

`typescript
import { FixedChunkStream } from '@kawaz/fixed-chunk-stream';

// Create a stream that outputs 1KB chunks
const chunkStream = new FixedChunkStream(1024);

// Use it in a pipeline
await sourceStream
.pipeThrough(chunkStream)
.pipeTo(destinationStream);
`

$3

By default, any remaining bytes that cannot form a complete chunk at the end of the stream are emitted as a smaller chunk. You can change this behavior by setting discardIncompleteChunks to true.

`typescript
// Discard incomplete chunks at the end of the stream
const chunkStream = new FixedChunkStream(1024, {
discardIncompleteChunks: true
});
`

$3

`typescript
// Example: Reading a file in chunks
const response = await fetch('large-file.bin');
const reader = response.body
.pipeThrough(new FixedChunkStream(1024))
.getReader();

while (true) {
const { done, value } = await reader.read();
if (done) break;

// Each value is a Uint8Array of exactly 1024 bytes
// (except possibly the last chunk if discardIncompleteChunks is false)
console.log('Chunk size:', value.length);
}
`

Development

This project uses Bun for development. Make sure you have it installed.

`bash


Install dependencies

bun install

Run tests

bun test

Build the project

bun run build
`

License

MIT License - see the LICENSE file for details

Author

Yoshiaki Kawazu

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature`)
5. Open a Pull Request

Support

If you have any questions or run into issues, please open an issue on the GitHub repository.