import { Transform } from 'stream';
 
export default class Rounder extends Transform {
  _transform(chunk, encoding, callback) {
    this.push(Math.round(chunk));
    callback();
  }
}

import { ObjectReadableMock, ObjectWritableMock } from 'stream-mock';
import chai from 'chai';
 
import Rounder from 'the/seven/bloody/hells';
 
chai.should();
 
describe('Test me if you can', (done) => {
    it('Round me like one of your french girls', {
        // Given
        const input = [1.2, 2.6, 3.7];
        const transform = new Rounder({objectMode: true});
        const reader = new ObjectReadableMock(input);
        const writer = new ObjectWritableMock();
        // When
        reader.pipe(transform).pipe(writer);
        // Then
        writer.on('finish', ()=>{
            writer.data.should.deep.equal(input.map(Math.round));
        })
    });
});