Why Supabase Auth handles identity - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize Supabase Auth client.

Supabase

const supabase = createClient([1], 'public-anon-key');

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

ADATABASE_URL

BSUPABASE_URL

CAPI_KEY

DAUTH_TOKEN

Attempts:

3 left

💡 Hint

Common Mistakes

Using API key instead of the project URL.

Confusing database URL with Supabase URL.

The Supabase client requires the project URL to connect to the backend services, including Auth.

2fill in blank

medium

Complete the code to sign in a user with email and password.

Supabase

const { data, error } = await supabase.auth.[1]({ email, password });

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

Aauthenticate

Bregister

CloginUser

DsignInWithPassword

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'register' instead of 'signInWithPassword'.

Using non-existent methods like 'authenticate'.

The method signInWithPassword is used to authenticate users with email and password in Supabase Auth.

3fill in blank

hard

Fix the error in the code to get the current authenticated user.

Supabase

const { data: { user }, error } = await supabase.auth.[1]();

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

AgetUser

BcurrentUser

Cuser

DgetCurrentUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'user' property directly which does not exist.

Using 'currentUser' which is not a Supabase method.

The correct method to retrieve the current user object is getUser() in Supabase Auth.

4fill in blank

hard

Fill both blanks to handle sign out and listen for auth state changes.

Supabase

await supabase.auth.[1]();
supabase.auth.onAuthStateChange((event, session) => { console.log(event, session); }, [2]);

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

AsignOut

BsignIn

CSIGNED_IN

DSIGNED_OUT

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'signIn' instead of 'signOut' to log out.

Listening for 'SIGNED_IN' event when expecting sign out.

Use signOut() to log out the user and listen for the SIGNED_OUT event to handle changes.

5fill in blank

hard

Fill all three blanks to update user metadata after authentication.

Supabase

const { data, error } = await supabase.auth.updateUser({ [1]: [2] });
console.log([3]);

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

Adata

Buser_metadata

Cerror

DnewMetadata

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong keys like 'data' instead of 'user_metadata'.

Logging the wrong variable after update.

Use user_metadata to update metadata, pass the new metadata object, and log the returned data.

Practice

1. What is the main purpose of Supabase Auth in an application?

easy

A. To manage user identity and authentication securely

B. To store large files and media

C. To create database tables automatically

D. To handle server backups

Solution

1. Step 1: Understand Supabase Auth's role

   Supabase Auth is designed to handle user login and identity management securely.

2. Step 2: Compare with other options

   Storing files, creating tables, and backups are handled by other Supabase services, not Auth.

3. Final Answer:

   To manage user identity and authentication securely -> Option A

4. Quick Check:

   Supabase Auth = user identity management [OK]

Hint: Auth means user login and identity management [OK]

Common Mistakes:

• Confusing Auth with file storage
• Thinking Auth creates database tables
• Assuming Auth handles backups

2. Which of the following is the correct way to initialize Supabase Auth in a JavaScript app?

easy

A. const supabase = new SupabaseAuth('url', 'key');

B. const supabase = createClient('url', 'key');

C. const supabase = supabase.auth('url', 'key');

D. const supabase = supabaseClient('url', 'key');

Solution

1. Step 1: Recall Supabase client initialization

   Supabase uses createClient(url, key) to initialize the client including Auth.

2. Step 2: Check other options

   Options B, C, and D use incorrect constructors or methods not in Supabase docs.

3. Final Answer:

   const supabase = createClient('url', 'key'); -> Option B

4. Quick Check:

   Use createClient() to initialize Supabase [OK]

Hint: Use createClient() to start Supabase Auth [OK]

Common Mistakes:

• Using new keyword incorrectly
• Calling auth() as a function to initialize
• Misspelling createClient

3. Given this code snippet, what will console.log(user.email) output after a successful login?

const { data, error } = await supabase.auth.signInWithPassword({ email: '[e-mail]', password: 'pass123' }); const user = data.user;

medium

A. An error object

B. undefined

C. null

D. '[e-mail]'

Solution

1. Step 1: Understand signInWithPassword result

   On success, data.user contains user info including email.

2. Step 2: Check user.email value

   Since login is successful, user.email matches the input email '[e-mail]'.

3. Final Answer:

   '[e-mail]' -> Option D

4. Quick Check:

   Successful login returns user email [OK]

Hint: Successful login returns user object with email [OK]

Common Mistakes:

• Assuming user is null on success
• Expecting error object instead of user
• Confusing undefined with null

4. What is wrong with this code snippet that tries to sign up a user?

const { data, error } = await supabase.auth.signUp({ email: '[e-mail]' });

medium

A. signUp method does not exist

B. Email format is invalid

C. Password is missing in signUp call

D. Await keyword is not allowed here

Solution

1. Step 1: Check signUp method requirements

   signUp requires both email and password to create a user.

2. Step 2: Identify missing parameter

   The code only provides email, missing password, causing failure.

3. Final Answer:

   Password is missing in signUp call -> Option C

4. Quick Check:

   signUp needs email and password [OK]

Hint: Always provide password when signing up [OK]

Common Mistakes:

• Forgetting password in signUp
• Thinking email alone is enough
• Misusing await outside async

5. How does Supabase Auth help an app track users without extra backend code?

hard

A. It provides built-in user sessions and tokens automatically

B. It requires manual database queries for each user

C. It stores user data only on the client side

D. It disables user tracking for privacy

Solution

1. Step 1: Understand Supabase Auth session management

   Supabase Auth automatically manages user sessions and tokens for identity.

2. Step 2: Compare with other options

   Manual queries or client-only storage are not needed; disabling tracking contradicts purpose.

3. Final Answer:

   It provides built-in user sessions and tokens automatically -> Option A

4. Quick Check:

   Supabase Auth auto-manages sessions [OK]

Hint: Supabase Auth auto-manages sessions and tokens [OK]

Common Mistakes:

• Thinking manual queries are needed
• Believing user data is client-only
• Assuming tracking is disabled