Firebase Cloud Functions

Firebase Cloud Functions allow you to run server-side code in response to HTTP requests, Firestore events, or callable requests from your client. This is useful for performing secure operations that should not be exposed to the client.

Create a Cloud Function

In this boilerplate, functions are located under /functions/src/yourfunction/. Each function has its own folder. For example, to create a task function:

      import * as functions from "firebase-functions";
      import {db} from "../firebase-admin";
      import { Timestamp } from "firebase-admin/firestore";

      export const createTask = functions.https.onCall(async (request) => {
          const userId = request.auth?.uid;
          const {data} = request.data;

          if (!userId) {
              throw new functions.https.HttpsError("unauthenticated", "User must be logged in");
          }

          if (!data.name) {
              throw new functions.https.HttpsError(
                  "invalid-argument",
                  "Missing required parameter: name"
              );
          }

          const now = Timestamp.now();

          const writeTask = {
              userId: userId,
              name: data.name,
              description: data.description ?? "",
              createdAt: now,
              updatedAt: now,
          };

          const docRef = await db.collection("tasks").add(writeTask);

          return { id: docRef.id, ...writeTask };
      });

This function:

Validates that the user is authenticated.
Validates required input parameters.
Writes a new task to Firestore using the Admin SDK.
Returns the newly created task.

Deploy the Function

Before your deploy, you need to import your function in functions/index.ts

To deploy your Cloud Function, run the following command from your project root:

cd functions
npm run deploy

Notes:

This will deploy all functions under /functions/src/.
After deployment, the functions can be called from the client using Firebase callable functions (Examples can be found under lib/serbices/tasks-functions.ts):

export const createTask = async (task: Partial<Task>, serverCustomToken: string): Promise<Task> => {
try {
  // Setup
  // https://next-firebase-auth-edge-docs.vercel.app/docs/usage/client-side-apis
  await setupFirebaseAuth(serverCustomToken);

  // Call the function
  const functions = getFunctions(getFirebaseApp())
  const myCallableFunction = httpsCallable(functions, Functions.CREATE_SITE);

  // Connect to the local emulator
  if (process.env.NEXT_PUBLIC_ENV == "local") {
      console.log("connecting emulator ..")
      connectFunctionsEmulator(functions, '127.0.0.1', 5001);
  }

  const response = await myCallableFunction({
      site: task
  })

  return response.data as Task
} catch (error) {
  console.error('Internal Error', error);
  throw error;
}
};

Next, we can cover Firebase Storage for uploading and retrieving files.

Firestore admin Storage

import * as functions from "firebase-functions"; import {db} from "../firebase-admin"; import { Timestamp } from "firebase-admin/firestore"; export const createTask = functions.https.onCall(async (request) => { const userId = request.auth?.uid; const {data} = request.data; if (!userId) { throw new functions.https.HttpsError("unauthenticated", "User must be logged in"); } if (!data.name) { throw new functions.https.HttpsError( "invalid-argument", "Missing required parameter: name" ); } const now = Timestamp.now(); const writeTask = { userId: userId, name: data.name, description: data.description ?? "", createdAt: now, updatedAt: now, }; const docRef = await db.collection("tasks").add(writeTask); return { id: docRef.id, ...writeTask }; });

export const createTask = async (task: Partial<Task>, serverCustomToken: string): Promise<Task> => { try { // Setup // https://next-firebase-auth-edge-docs.vercel.app/docs/usage/client-side-apis await setupFirebaseAuth(serverCustomToken); // Call the function const functions = getFunctions(getFirebaseApp()) const myCallableFunction = httpsCallable(functions, Functions.CREATE_SITE); // Connect to the local emulator if (process.env.NEXT_PUBLIC_ENV == "local") { console.log("connecting emulator ..") connectFunctionsEmulator(functions, '127.0.0.1', 5001); } const response = await myCallableFunction({ site: task }) return response.data as Task } catch (error) { console.error('Internal Error', error); throw error; } };