Error: Unexpected data on Writable Stream

[EFXPROMedia]

I keep getting the error Errors:

Unexpected data on Writable Stream

and

**(sharp:37544): GLib-CRITICAL : 16:05:21.651: g_hash_table_lookup: assertion 'hash_table != NULL' failed

My code is:

if (req.query.format != null) {
	const imagePath = "./" + req._parsedOriginalUrl.pathname;
	const read = fs.createReadStream(path.resolve(__dirname, imagePath)).setEncoding('base64');
	const transform = Sharp(path.resolve(__dirname, imagePath)).resize(200, 200, {
		fit: "cover"
	}).jpeg({
		quality: 20
	}).toBuffer((err, data, info) => {
		console.log("FILE INFO", info)
	});
	const write = fs.createWriteStream("./"+ req.params.imageName);
	read.pipe(transform).pipe(write);
}

Is there anything wrong with my code or is this is an error with the package.

[lovell]

Hello, you're providing a filesystem path to the sharp constructor as the input and then also attempting to pipe data into it; choose one.

(The g_hash_table_lookup warning is because the Node process exited without waiting for in-flight async tasks to complete.)

[EFXPROMedia]

I am not sure if I understood, the documentation explains to get a readable stream of the file then use sharp with the readable stream as input then pipe it to the response! but it doesnt matter what I do I get an error. Should I be using Sync methods for this operation?

I am basically trying to read an image from the GET response and transform.resize() > pipe it to the response using sharp!

[lovell]

A sharp instance can be treated as a Writable stream (for input), a Readable stream (for output), a Transform stream (for both input and output) or not a stream at all if you provide filesystem paths or a Buffer.

Here's you example re-worked to use filesystem paths:

	const imagePath = "./" + req._parsedOriginalUrl.pathname;
	const transform = Sharp(path.resolve(__dirname, imagePath)).resize(200, 200, {
		fit: "cover"
	}).jpeg({
		quality: 20
	}).toFile("./"+ req.params.imageName, (err, info) => {
		console.log("FILE INFO", info)
	});

...and here's your example re-worked to use a Transform stream:

	const imagePath = "./" + req._parsedOriginalUrl.pathname;
	const read = fs.createReadStream(path.resolve(__dirname, imagePath));
	const transform = Sharp().resize(200, 200, {
		fit: "cover"
	}).jpeg({
		quality: 20
	});
	const write = fs.createWriteStream("./"+ req.params.imageName);
	read.pipe(transform).pipe(write);

[EFXPROMedia]

This helped me to figure out thanks... in my case I rendered the image on the response so I piped it to the response instead of the write and it works!

read.pipe(transform).pipe(res);

[lovell]

I've just spotted that this was a cross-post of a question originally asked at https://stackoverflow.com/questions/54635393/render-opmised-images-with-node-js-and-express-with-sharp-or-canvas

Please (1) mention existing StackOverflow questions when opening new issues on GitHub and (2) now is a good time for you to update your original StackOverflow question to include the answer to help others.