File Upload from API Routes Next.js not working - node.js

Question

I'm trying to upload a file to my server which I'm successfully able to do with my code, but I get a this console output from it:
API resolved without sending a response for /api/upload, this may result in a stalled requests.
The file is successfully put into the folder though.
I don't quite understand how I am not sending a response as to me I am.
What am I doing wrong?
Here is my form code:
const axios = require("axios").default;
class VideoUploadForm extends React.Component {
constructor(props) {
super(props);
this.state = {
file: null,
uploaded: false
};
}
onChangeHandler = event => {
this.setState({
selectedFile: event.target.files[0],
loaded: 0
});
};
onClickHandler = () => {
const data = new FormData();
data.append("video", this.state.selectedFile);
axios
.post("/api/upload", data, {
headers: {
"Content-Type": "multipart/form-data"
}
})
.then(function(response) {
console.log(response);
})
.catch(function(error) {
console.log(error);
});
};
render() {
return (
<div>
<form
action="#"
method="post"
encType="multipart/form-data"
target="transFrame"
>
<input type="file" name="video" onChange={this.onChangeHandler} />
<button onClick={this.onClickHandler}>upload</button>
</form>
<iframe
width="200"
height="100"
name="transFrame"
id="transFrame"
></iframe>
</div>
);
}
}
export default VideoUploadForm;
and the API
import multer from "multer";
export const config = {
api: {
bodyParser: false
}
};
var storage = multer.diskStorage({
destination: function(req, file, cb) {
cb(null, "public");
},
filename: function(req, file, cb) {
cb(null, "video.mp4");
}
});
var upload = multer({ storage: storage });
export default async (req, res) => {
upload.single("video")(req, {}, err => {
res.send(req.file.path);
res.end();
console.log(req.file); // do something with the file
});
};

Answer 1

This is where the problem is
res.send(req.file.path);
res.end();
res.send implicitly calls res.write followed by res.end. You should remove the second res.end.

Answer 2

Try
var upload = multer(storage);