Firebase CLI setup - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Firebase CLI Authentication

What happens when you run firebase login for the first time?

A It opens a browser window to authenticate your Google account and stores credentials locally.

B It immediately creates a new Firebase project without authentication.

C It installs Firebase CLI globally without asking for credentials.

D It deletes all existing Firebase projects linked to your account.

💡 Hint

Think about how CLI tools usually authenticate users with cloud services.

Running firebase login opens a browser for Google sign-in and saves your credentials locally for future commands.

❓ Configuration

intermediate

Correct Firebase Project Initialization Command

You want to initialize a Firebase project in your local folder. Which command correctly starts this process?

A firebase init

B firebase start

C firebase create

D firebase deploy

💡 Hint

Initialization usually means setting up configuration files.

firebase init sets up Firebase configuration files and services in your project folder.

❓ Architecture

advanced

Firebase CLI and Multiple Projects

You have two Firebase projects and want to switch between them using Firebase CLI. What is the best way to manage this?

A Change the project ID manually in the <code>.firebaserc</code> file without CLI commands.

B Delete one project and recreate it with the other name.

C Run <code>firebase login</code> again for each project.

D Use <code>firebase use --add</code> to add and switch between projects locally.

💡 Hint

Think about how CLI tools handle multiple environments or projects.

firebase use --add lets you add multiple projects and switch between them easily in your local setup.

❓ security

advanced

Firebase CLI Token Usage for CI/CD

For automated deployment in a CI/CD pipeline, which Firebase CLI authentication method is recommended?

A Store your Google password in plain text in the pipeline configuration.

B Run <code>firebase login</code> interactively on the CI server.

C Use a Firebase CI token generated by <code>firebase login:ci</code> and set it as an environment variable.

D Use the <code>firebase logout</code> command before deployment.

💡 Hint

Interactive login is not possible in automated pipelines.

Generating a CI token with firebase login:ci allows secure non-interactive authentication in pipelines.

❓ service_behavior

expert

Effect of Running 'firebase deploy' Without Initialization

What happens if you run firebase deploy in a folder that has no Firebase project initialized?

A It automatically creates a new Firebase project and deploys default settings.

B The CLI shows an error saying no Firebase project is configured and stops deployment.

C It deploys to the last used Firebase project regardless of the current folder.

D It deletes all Firebase projects linked to your account.

💡 Hint

Think about what is needed before deploying with Firebase CLI.

Without initialization, Firebase CLI cannot find project settings and will show an error to prevent accidental deployment.

Practice

1. What is the main purpose of the Firebase CLI tool?

easy

A. To create Firebase projects online automatically

B. To write Firebase database rules only

C. To manage Firebase projects from your computer

D. To replace the Firebase console website

Solution

1. Step 1: Understand Firebase CLI role

   The Firebase CLI is a command-line tool that lets you control Firebase projects locally on your computer.

2. Step 2: Compare options

   Options B, C, and D describe limited or incorrect roles. Only To manage Firebase projects from your computer correctly states the main purpose.

3. Final Answer:

   To manage Firebase projects from your computer -> Option C

4. Quick Check:

   Firebase CLI = Manage projects locally [OK]

Hint: Firebase CLI controls projects from your PC, not just online [OK]

Common Mistakes:

• Thinking Firebase CLI only edits database rules
• Believing it creates projects automatically online
• Confusing it with the Firebase web console

2. Which command correctly installs the Firebase CLI using npm?

easy

A. install firebase-cli -npm

B. npm install -g firebase-tools

C. npm firebase install -g

D. firebase install npm-tools

Solution

1. Step 1: Recall npm install syntax

   The correct npm command to install a global package is 'npm install -g package-name'.

2. Step 2: Match with Firebase CLI package

   The Firebase CLI package name is 'firebase-tools', so the correct command is 'npm install -g firebase-tools'.

3. Final Answer:

   npm install -g firebase-tools -> Option B

4. Quick Check:

   npm install -g firebase-tools = Correct install command [OK]

Hint: Use 'npm install -g firebase-tools' to install globally [OK]

Common Mistakes:

• Mixing order of npm and firebase keywords
• Forgetting the '-g' flag for global install
• Using incorrect package names

3. What will happen if you run firebase init in your project folder?

medium

A. It deploys your app to Firebase hosting immediately

B. It deletes all Firebase projects linked to your account

C. It logs you out of Firebase CLI

D. It initializes Firebase in the folder by creating config files

Solution

1. Step 1: Understand 'firebase init' purpose

   This command sets up Firebase in your local folder by creating necessary config files and asking which Firebase features to enable.

2. Step 2: Eliminate wrong options

   Options A, B, and D describe actions unrelated to initialization. Deploying is done with 'firebase deploy', not 'init'.

3. Final Answer:

   It initializes Firebase in the folder by creating config files -> Option D

4. Quick Check:

   firebase init = Setup project locally [OK]

Hint: 'firebase init' sets up config files, not deploy or delete [OK]

Common Mistakes:

• Confusing 'init' with 'deploy'
• Thinking it deletes projects
• Assuming it logs out the user

4. You ran firebase deploy but got an error saying 'No Firebase project detected'. What is the likely cause?

medium

A. You did not run firebase init to set up the project

B. You forgot to install Node.js on your computer

C. You are not logged into Firebase CLI

D. Your internet connection is offline

Solution

1. Step 1: Analyze error message

   The error 'No Firebase project detected' means the CLI cannot find project config files in the folder.

2. Step 2: Identify missing setup step

   Without running 'firebase init', the project folder lacks Firebase config files, causing this error.

3. Final Answer:

   You did not run firebase init to set up the project -> Option A

4. Quick Check:

   Missing init causes 'No Firebase project detected' error [OK]

Hint: Run 'firebase init' before deploy to create config files [OK]

Common Mistakes:

• Assuming login or internet issues cause this error
• Ignoring the need to initialize project first
• Thinking Node.js installation affects this error

5. You want to deploy only your Firebase Functions without affecting Hosting or Firestore. Which command should you use?

hard

A. firebase deploy --only functions

B. firebase deploy --only hosting

C. firebase deploy --only firestore

D. firebase deploy --all

Solution

1. Step 1: Understand deploy options

   The Firebase CLI allows deploying specific services using the '--only' flag followed by the service name.

2. Step 2: Select correct service for Functions

   To deploy only Functions, use '--only functions'. Other options deploy different services or all.

3. Final Answer:

   firebase deploy --only functions -> Option A

4. Quick Check:

   Deploy specific service with '--only functions' [OK]

Hint: Use '--only functions' to deploy just Functions [OK]

Common Mistakes:

• Using '--only hosting' or '--only firestore' by mistake
• Using '--all' deploys everything, not just Functions
• Not using '--only' flag and deploying all services