chokidarで任意のフォルダのファイル追加・変更を監視するサンプル

chokidar-file-watch.ts

import chokidar from 'chokidar'; // @types/chokidar
import parse from 'csv-parse'; // @types/csv-parse
import fs from 'fs'; // @types/node

chokidar.watch('S:/chokidar', { ignored: /[\/\\]\./ }).on('all', (event: string, path: string) => {
  if (event === 'add' || event === 'change') {
    if (new RegExp(/\.(csv|txt)$/).test(path)) {
      console.log(event, path);

      fs.readFile(path, 'utf8', (err, data: string) => {
        if (err) { throw err; }
        console.log(data);

        parse(data, { columns: true, auto_parse: true }, (err, results: Array<ObjectFromCsv>) => {
          if (err) { throw err; }
          const now = new Date().getTime();
          const newResults = results.map(result => Object.assign(result, { 'timestamp': now }));
          console.log(newResults);

        });

      });

    }
  }
});


interface ObjectFromCsv {
  [key: string]: string | number | boolean | null;
}