useFileReadAsDataURL.js

function useFileReadAsDataURL(file) {
	const [dataURL, setDataURL] = React.useState("");
	const fileReaderRef = React.useRef(new FileReader());

	React.useEffect(() => {
		const fileReader = fileReaderRef.current;

		const setResult = () => {
			setDataURL(fileReader.result);
		};

		if (file && file instanceof File) {
			fileReader.readAsDataURL(file);
		}

		fileReader.addEventListener("load", setResult, false);

		return () => {
			fileReader.removeEventListener("load", setResult, false);
		};
	}, [file]);

	return dataURL;
}