export async function fetchSchemas()

in src/schema/firefox-schemas-import.js [774:811]
32 lines of code
3 McCabe index (conditional complexity)

export async function fetchSchemas({ inputPath, outputPath }) {
  const inputFileStat = fs.statSync(inputPath);
  if (inputFileStat.isDirectory()) {
    return fetchSchemasFromDir({ inputPath, outputPath });
  }

  const openZip = util.promisify(yauzl.open);
  const zipfile = await openZip(inputPath);
  const openReadStream = util.promisify(zipfile.openReadStream.bind(zipfile));
  const writeStreamsPromises = [];

  return new Promise((resolve, reject) => {
    zipfile
      .on('entry', async (entry) => {
        if (inner.isBrowserSchema(entry.fileName)) {
          const filePath = path.join(outputPath, path.basename(entry.fileName));

          // Collect the file streams we're creating here to be able to wait
          // for them to ensure we're closing their streams
          const destFileStream = fs.createWriteStream(filePath);
          writeStreamsPromises.push(
            new Promise((res) => {
              destFileStream.on('close', res);
            })
          );
          const readStream = await openReadStream(entry);

          readStream.pipe(destFileStream);
        }
      })
      .on('error', (error) => {
        reject(error);
      })
      .on('end', () => {
        Promise.all(writeStreamsPromises).then(resolve, reject);
      });
  });
}