text: const fs = require('fs');
  const path = require('path');
  
  const dir = path.dirname(__filename);
  const files = fs.readdirSync(dir);
  let total = 0; let passed = 0;
  for (const file of files) {
      if (file === 'index.js') continue;
      console.log(`Running ${file} ...`);
      ++total;
      try {
          require(path.join(dir, file));
          console.log(`Running ${file} done.`);
          ++passed;
      }
      catch (err) {
          console.error(err);
          console.error(`Running ${file} failed.`);
      }
  }
  console.log(`All tests completed. (${passed}/${total})`);
  