taoyuan/memstreams

# Memory Stream

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> Memory Streams library for JavaScript based on readable-stream

> This library is forked from
> [stream-mock](https://github.com/b4nst/stream-mock)

## Features

- Create a
  [readable stream](https://nodejs.org/api/stream.html#stream_readable_streams)
  from any iterable.
- Create a
  [writable stream](https://nodejs.org/api/stream.html#stream_writable_streams)
  that puts its data at your disposal.
- Create a
  [duplex stream](https://nodejs.org/api/stream.html#stream_duplex_and_transform_streams)
  that combines a readable and writable stream together.
- Can operate both in
  [object](https://nodejs.org/api/stream.html#stream_object_mode) and normal (
  [Buffer](https://nodejs.org/api/buffer.html#buffer_buf_length) ) mode.
- Forward writable to readable through event `write` to replace `queue`

## Quick start

```shell
yarn add memstreams
```

Or, if you are more a `npm` person

```shell
npm i memstreams
```

### Basic usage

You are building an awesome brand new
[Transform stream](https://nodejs.org/api/stream.html#stream_duplex_and_transform_streams)
that rounds all your values.

`rounder.ts`

```javascript
import {Transform} from 'stream';

export class Rounder extends Transform {
  _transform(chunk, encoding, callback) {
    this.push(Math.round(chunk));
    callback();
  }
}
```

Now you need / want to test it.

`example.ts`

```typescript
import {ObjectReader, ObjectWriter} from 'memstreams';
import {Rounder} from './rounder';

const input = [1.2, 2.6, 3.7];
const transform = new Rounder({objectMode: true});
const reader = new ObjectReader(input, {autoEnd: true});
const writer = new ObjectWriter();

reader.pipe(transform).pipe(writer);

writer.on('finish', () => {
  console.log(writer.data);
});
```

---

## License

MIT