const JSONSplitStream = require('json-split-stream');

const chunker = new JSONSplitStream();  // is a Duplex stream

chunker.write('[1,2,3]{"a":12}');
chunker.read(); // => '[1,2,3]'
chunker.read(); // => '{"a":12}'
chunker.read(); // => null

const chunker = new JSONSplitStream({ storeData: false });
chunker.on('finishedJSON', ({ jsonEnd }) => {
  console.log('ended at', jsonEnd);
});

chunker.write('[1,2,3]{"a":');
chunker.write('12}');

// Prints:
ended at 7
ended at 15