Function deployment in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to deploy a Firebase function named 'helloWorld'.

Firebase

exports.helloWorld = functions.[1]((req, res) => {
  res.send('Hello from Firebase!');
});

Drag options to blanks, or click blank then click option'

AhttpsCallable

Bfirestore.document

Chttps.onRequest

Ddatabase.ref

Attempts:

3 left

💡 Hint

Common Mistakes

Using firestore triggers instead of HTTP triggers.

Using database triggers for HTTP functions.

The correct method to deploy an HTTP function in Firebase is https.onRequest.

2fill in blank

medium

Complete the command to deploy all Firebase functions.

Firebase

firebase [1] --only functions

Drag options to blanks, or click blank then click option'

Adeploy

Bserve

Cinit

Demulators:start

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'serve' which runs local emulators.

Using 'init' which initializes a project.

The firebase deploy command uploads and deploys your functions to Firebase.

3fill in blank

hard

Fix the error in the function trigger type to deploy an HTTP function.

Firebase

exports.myFunction = functions.[1]((req, res) => {
  res.send('Done');
});

Drag options to blanks, or click blank then click option'

Ahttps.onRequest

Bdatabase.ref

Cfirestore.document

Dstorage.object

Attempts:

3 left

💡 Hint

Common Mistakes

Using database or Firestore triggers for HTTP functions.

Using storage triggers for HTTP functions.

HTTP functions require the https.onRequest trigger.

4fill in blank

hard

Fill both blanks to deploy only the 'auth' and 'firestore' Firebase emulators.

Firebase

firebase emulators:start --only [1],[2]

Drag options to blanks, or click blank then click option'

Aauth

Bfunctions

Cfirestore

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Including functions emulator when not required.

Using database instead of firestore.

The auth and firestore emulators are started by specifying them with --only.

5fill in blank

hard

Fill all three blanks to initialize Firebase functions with TypeScript and ESLint.

Firebase

firebase init functions
? What language would you like to use to write Cloud Functions? [1]
? Do you want to use ESLint to catch probable bugs and enforce style? [2]
? Do you want to install dependencies with npm now? [3]

Drag options to blanks, or click blank then click option'

AJavaScript

BTypeScript

CYes

DNo

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing JavaScript instead of TypeScript.

Skipping ESLint setup.

Not installing dependencies immediately.

Choose TypeScript for language, Yes to use ESLint, and Yes to install dependencies immediately.

Practice

1. What does the command firebase deploy --only functions do?

easy

A. Uploads and deploys only your Firebase functions to the cloud

B. Deletes all your Firebase functions from the cloud

C. Deploys your entire Firebase project including database and hosting

D. Runs your Firebase functions locally without uploading

Solution

1. Step 1: Understand the command purpose

   The command firebase deploy --only functions is used to upload and deploy only the cloud functions part of your Firebase project.

2. Step 2: Compare with other options

   It does not delete functions, deploy the entire project, or run functions locally. It specifically deploys functions to the cloud.

3. Final Answer:

   Uploads and deploys only your Firebase functions to the cloud -> Option A

4. Quick Check:

   Deploy only functions = uploads functions [OK]

Hint: Deploy functions only means upload cloud functions [OK]

Common Mistakes:

• Confusing deploy with delete
• Thinking it deploys the whole project
• Assuming it runs functions locally

2. Which of the following is the correct command to deploy only a single function named sendEmail?

easy

A. firebase deploy --only functions

B. firebase deploy --only functions:sendEmail

C. firebase deploy --only sendEmail

D. firebase deploy --functions sendEmail

Solution

1. Step 1: Recall syntax for deploying a single function

   To deploy a single function, you use firebase deploy --only functions:functionName. Here, functionName is sendEmail.

2. Step 2: Match the correct option

   firebase deploy --only functions:sendEmail matches this syntax exactly. Other options either deploy all functions or use incorrect flags.

3. Final Answer:

   firebase deploy --only functions:sendEmail -> Option B

4. Quick Check:

   Single function deploy uses --only functions:functionName [OK]

Hint: Use --only functions:functionName to deploy one function [OK]

Common Mistakes:

• Omitting 'functions:' prefix
• Using wrong flag like --functions
• Deploying all functions instead of one

3. Given the command firebase deploy --only functions:processOrder, what happens if processOrder function code has a syntax error?

medium

A. The function deploys but crashes when called

B. The deployment succeeds but disables the function automatically

C. Firebase ignores the error and deploys successfully

D. The deployment fails and shows an error message

Solution

1. Step 1: Understand deployment behavior on syntax errors

   If the function code has a syntax error, Firebase detects it during deployment and stops the process, showing an error.

2. Step 2: Eliminate incorrect options

   Firebase does not deploy faulty code, so options A, C, and D are incorrect.

3. Final Answer:

   The deployment fails and shows an error message -> Option D

4. Quick Check:

   Syntax error blocks deployment = fail and error [OK]

Hint: Syntax errors stop deployment with error message [OK]

Common Mistakes:

• Assuming deployment succeeds despite errors
• Thinking Firebase auto-fixes errors
• Believing function disables automatically

4. You run firebase deploy --only functions but your new function notifyUser does not appear in the cloud. What is the most likely cause?

medium

A. You forgot to export notifyUser in your functions code

B. You deployed with the wrong Firebase project ID

C. You need to restart your local machine before deploying

D. Firebase does not support deploying new functions

Solution

1. Step 1: Check function export in code

   For Firebase to deploy a function, it must be exported properly in your code. If notifyUser is not exported, it won't deploy.

2. Step 2: Evaluate other options

   Wrong project ID would cause deployment failure or deploy to wrong place, restarting is unnecessary, and Firebase supports new functions.

3. Final Answer:

   You forgot to export notifyUser in your functions code -> Option A

4. Quick Check:

   Functions must be exported to deploy [OK]

Hint: Always export new functions to deploy them [OK]

Common Mistakes:

• Not exporting the function in code
• Assuming restart fixes deployment
• Ignoring project configuration

5. You want to deploy two functions named createUser and deleteUser without deploying others. Which command should you use?

hard

A. firebase deploy --only functions:createUser;deleteUser

B. firebase deploy --only functions:createUser deleteUser

C. firebase deploy --only functions:createUser,deleteUser

D. firebase deploy --only functions:createUser deleteUser --force

Solution

1. Step 1: Understand syntax for multiple functions deployment

   To deploy multiple specific functions, list them separated by commas after functions: with no spaces.

2. Step 2: Identify correct option

   firebase deploy --only functions:createUser,deleteUser uses correct comma-separated syntax. Other options use spaces or semicolons which are invalid.

3. Final Answer:

   firebase deploy --only functions:createUser,deleteUser -> Option C

4. Quick Check:

   Multiple functions deploy uses comma-separated list [OK]

Hint: Use commas to list multiple functions in --only flag [OK]

Common Mistakes:

• Using spaces instead of commas
• Using semicolons to separate functions
• Adding unnecessary flags like --force