firebase-micorservice-function-save-tmp-file-upload-bucket.ts

import functions = require('firebase-functions');
import fs = require('fs');
import os = require('os');
import path = require('path');
const admin = require('firebase-admin');
admin.initializeApp();
const bucket = admin.storage().bucket();

export const textToSpeechRequest = functions.https.onCall((data: any, context: any) => {
  const destName = 'test.txt';
  const tempFile = path.join(os.tmpdir(), destName);

  return new Promise((resolve, reject) => {

    fs.writeFile(tempFile, "Hey there!", function(err) {
      if (err) {
        console.log(err);
        reject(`error_write_tmp: ${tempFile}`);
      }
      console.log(tempFile, destName);

      return bucket.upload(tempFile, { destination: destName })
        .then(() => {
          resolve({
            query:data,
            answer:destName
          });
        }).catch((err1: any) => {
          reject('Failed to upload: ' + JSON.stringify(err1));
        });
    });
  });
})