How to rewrite a class component with componentWillReceiveProps into a functional component

Question

I'm trying to refactor this React component into a functional component but am not too sure how to handle the componentWillReceiveProps part. I've looked up a few guides and past questions but can't find anything on this aspect specifically.

import React from "react";

class Thumbnail extends React.Component {
  state = {
    loading: false,
    thumb: undefined,
  };

  componentWillReceiveProps(nextProps) {
    if (!nextProps.file) {
      return;
    }

    this.setState({ loading: true }, () => {
      let reader = new FileReader();

      reader.onloadend = () => {
        this.setState({ loading: false, thumb: reader.result });
      };

      reader.readAsDataURL(nextProps.file);
    });
  }

  render() {
    const { file } = this.props;
    const { loading, thumb } = this.state;

    if (!file) {
      return null;
    }

    if (loading) {
      return <p>loading...</p>;
    }

    return (
      <img
        src={thumb}
        alt={file.name}
        className="img-thumbnail mt-2"
        height={200}
        width={200}
      />
    );
  }
}