Blob and File seem to be missing?

[wmertens]

When using FormData to upload a file in the browser, you can pass it a File which is actually a Blob and that can lazily represent a huge file.

This isn't possible in Node, you need to use something like https://github.com/form-data/form-data to work with memory efficiently.

Is Blob support planned?

[Trott]

Blob was added in Node.js 18.

[wmertens]

Argh, totally missed that, sorry. "blob" and "file" are hard to search on 😅.

But File is still missing, right? Or is there some other way to lazily access a file as a Blob?

[aduh95]

The File class has not been implemented in Node.js (and there doesn't seem to be a good use case for it in Node.js). As of Node.js v16.7.0, you can create a Blob that contains the file content using the following utility:

import { createReadStream } from 'node:fs';
import { blob } from 'node:stream/consumers';

const myFile = await blob(createReadStream('path/to/my/file'));

[wmertens]

Hmm but that will load the entire file into memory https://github.com/nodejs/node/blob/27ecf1d94cc0c6eaae09e30b3c8a1251d1b4dd46/lib/stream/consumers.js#L29-L34

The Blob API should make it possible to append a 2GB file to a FormData instance without loading it into memory, right? Is that something that Node can support?

[targos]

I'm in favor of having an implementation of File in Node.js. We just need a volunteer to do it.
The issue for it is nodejs/node#39015