text: const { Transform } = require ( 'stream' );
  
  const commaSplitter = new Transform ( {
                                            readableObjectMode: true,
  
                                            transform ( chunk, encoding, callback ) {
                                                this.push ( chunk.toString ().trim ().split ( ',' ) );
                                                callback ();
                                            }
                                        } );
  
  const arrayToObject = new Transform ( {
                                            readableObjectMode: true,
                                            writableObjectMode: true,
  
                                            transform ( chunk, encoding, callback ) {
                                                const obj = {};
                                                for ( let i = 0 ; i < chunk.length ; i += 2 ) {
                                                    obj[chunk[i]] = chunk[i + 1];
                                                }
                                                this.push ( obj );
                                                callback ();
                                            }
                                        } );
  
  const objectToString = new Transform ( {
                                             writableObjectMode: true,
  
                                             transform ( chunk, encoding, callback ) {
                                                 this.push ( JSON.stringify ( chunk ) + '\n' );
                                                 callback ();
                                             }
                                         } );
  
  process.stdin.push( 'a,b,c,d' );
  
  process.stdin
      .pipe ( commaSplitter )
      .pipe ( arrayToObject )
      .pipe ( objectToString )
      .pipe ( process.stdout );