DeprecationWarning when piping to createWriteStream

[Martijn Saly]

I'm using the recommended? way to stream a request to a file, and use await to wait until I can move to downloading the next file in my queue.

const r = request(file.url);
r.pipe(fs.createWriteStream(file.target));
await r;

Simple enough. And it absolutely completely works. But, occasionally I get a warning:

DeprecationWarning: Calling an asynchronous function without callback is deprecated

Does it need a callback then? And where, what should I put into it?

Also, I'm a noob on node (expert on general javascript though) so I might not be doing it correctly. If that's the case, please do show me a correct(er) way to "just" download a binary file and wait for it.

I'm on NodeJS 7.10 and Windows 10, if that helps.

[Nicolai Kamenzky]

Please do not use request-promise-native for streaming the response. Use request directly.

See the request-promise README for a little more detail where it says that “STREAMING THE RESPONSE (e.g. .pipe(...)) is DISCOURAGED”.

You can use request-promise-native and request alongside in your project. Depending on what kind of request you do you can just use one or the other.

[Martijn Saly]

Seems wasteful to install two components that do exactly the same. Can't this issue just be fixed?

[Nicolai Kamenzky]

Of course. Stay tuned for the fix of the issue over on request-promise.

Btw while you wait: Technically you are already installing request. request-promise-native is just an extension that adds promise capabilities to request. request is always the library that does the actual heavy lifting.