【React】CSVをアップロードしてFirestoreに保存する

import { render } from '@testing-library/react';
import { useCallback } from 'react';
import { useDropzone } from 'react-dropzone';
import { readString } from 'react-papaparse';
import { initializeApp, getApps } from "firebase/app";
import { collection, addDoc, getFirestore } from "firebase/firestore";


const firebaseConfig = {
  apiKey: process.env.REACT_APP_API_KEY,
  authDomain: process.env.REACT_APP_AUTH_DOMAIN,
  projectId: process.env.REACT_APP_PROJECT_ID,
};

if (!getApps().length) {
  const app = initializeApp(firebaseConfig);
}

const db = getFirestore();

function App() {
  const onDrop = useCallback((acceptedFiles) => {
    acceptedFiles.forEach((file) => {
      const reader = new FileReader()

      reader.onabort = () => console.log('file reading was aborted');
      reader.onerror = () => console.log('file reading has failed');
      reader.onload = () => {
        const binaryStr = reader.result;

        readString(binaryStr, {
          worker: true,
          complete: (results) => {
            results.data.map((row) => {
              addDoc(collection(db, "users"), {
                name: row[0],
                country: row[1],
                age: row[2]
              });
            });
          }
        });
      }
      reader.readAsText(file)
    });

  }, []);

  const {getRootProps, getInputProps, isDragActive} = useDropzone({onDrop});

  return (
    <div className="App">
      <div {...getRootProps()}>
        <input {...getInputProps()} />
        {
          isDragActive ?
            <p>Drop the files here ...</p> :
            <p>Drag 'n' drop some files here, or click to select files</p>
          }
        </div>
      </div>
    );
}

export default App;