How to read a file from Firebase Storage in Firebase Functions

Let's say you have a CSV file someone uploads from a UI, that gets saved to Firebase storage; details on how to do this here.

How do you then read and process that file on the server?

You can access the bucket from the firebase-admin library, and then download the file in memory. What you do with the file then is up to you!

import functions from 'firebase-functions';
import { initializeApp } from 'firebase-admin/app';
import { getStorage } from 'firebase-admin/storage';

initializeApp();

export const processCSV = functions
  .runWith({
    timeoutSeconds: 540
  })
  .storage.object()
  .onFinalize(async object => {
    functions.logger.log(object);

    const bucket = getStorage().bucket();
    const csvFile = await bucket.file(object.name).download();
    functions.logger.log(csvFile.toString());
  });