fetchOnceAndSaveToDiskWithBuffer

fetchOnceAndSaveToDiskWithBuffer.js

async function fetchOnceAndSaveToDiskWithBuffer(url, filename) {
  return new Promise(resolve => {
    if (fs.existsSync(filename)) {
      resolve(readFile(filename));
      
      return;
    }
    
    const file = fs.createWriteStream(filename);
    
    console.log(`  * Downloading from: ${url}`);
    
    https.get(url, (response) => {
      const unzip = zlib.createGunzip();
      response.pipe(unzip).pipe(file);
      unzip.on('end', () => {
        resolve(readFile(filename));
      });
    });
  });
}