Stream response to file using Fetch API and fs.createWriteStream

I’m creating an Electron application and I want to stream an image to a file (so basically download it).

I want to use the native Fetch API because the request module would be a big overhead.

But there is no pipe method on the response, so I can’t do something like

fetch('https://imageurl.jpg')
    .then(response => response.pipe(fs.createWriteStream('image.jpg')));

So how can I combine fetch and fs.createWriteStream?

Answer

I got it working. I made a function which transforms the response into a readable stream.

const responseToReadable = response => {
    const reader = response.body.getReader();
    const rs = new Readable();
    rs._read = async () => {
        const result = await reader.read();
        if(!result.done){
            rs.push(Buffer.from(result.value));
        }else{
            rs.push(null);
            return;
        }
    };
    return rs;
};

So with it, I can do

fetch('https://imageurl.jpg')
    .then(response => responseToReadable(response).pipe(fs.createWriteStream('image.jpg')));