sheetjs/docbits/31_writestream.md

### Streaming Write

The streaming write functions are available in the `XLSX.stream` object.  They
take the same arguments as the normal write functions but return a Readable
Stream.  They are only exposed in NodeJS.

- `XLSX.stream.to_csv` is the streaming version of `XLSX.utils.sheet_to_csv`.
- `XLSX.stream.to_html` is the streaming version of `XLSX.utils.sheet_to_html`.
- `XLSX.stream.to_json` is the streaming version of `XLSX.utils.sheet_to_json`.

<details>
  <summary><b>nodejs convert to CSV and write file</b> (click to show)</summary>

```js
var output_file_name = "out.csv";
var stream = XLSX.stream.to_csv(worksheet);
stream.pipe(fs.createWriteStream(output_file_name));
```

</details>

<details>
  <summary><b>nodejs write JSON stream to screen</b> (click to show)</summary>

```js
/* to_json returns an object-mode stream */
var stream = XLSX.stream.to_json(worksheet, {raw:true});

/* the following stream converts JS objects to text via JSON.stringify */
var conv = new Transform({writableObjectMode:true});
conv._transform = function(obj, e, cb){ cb(null, JSON.stringify(obj) + "\n"); };

stream.pipe(conv); conv.pipe(process.stdout);
```

</details>

<https://github.com/sheetjs/sheetaki> pipes write streams to nodejs response.