uploadCourse.ts

async function uploadCourseThumbnail(path: string) {
  const fileID = createID();
  const file = storage.file(`${fileID}.png`);

  file.makePublic();

  return new Promise((resolve, reject) => {
    const publicUrl = file.publicUrl();

    fs.createReadStream(path)
      .pipe(file.createWriteStream({
        metadata: {
          contentType: "image/png",
        }
      }))
      .on("error", (err) => {
        reject(err);
      })
      .on("close", () => {
        resolve(publicUrl);
      });
  });
}