Initializing Supabase client - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Supabase client creation function.

Supabase

import { createClient } from '[1]';

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

Asupabase-js

Bsupabase

C@supabase/supabase-js

Dsupabase-client

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'supabase' or 'supabase-js' without the '@supabase/' prefix.

Trying to import from 'supabase-client' which does not exist.

The Supabase client is created by importing createClient from the official package @supabase/supabase-js.

2fill in blank

medium

Complete the code to initialize the Supabase client with the URL.

Supabase

const supabase = createClient(process.env.[1], 'your-anon-key');

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

ASUPABASE_URL

BsupabaseUrl

CSUPABASE_API_URL

Dsupabase_url

Attempts:

3 left

💡 Hint

Common Mistakes

Using camelCase or lowercase variable names.

Confusing the URL variable with the anon key.

The environment variable SUPABASE_URL typically holds the Supabase project URL.

3fill in blank

hard

Fix the error in the code to correctly initialize the Supabase client with environment variables.

Supabase

const supabase = createClient(process.env.[1], process.env.SUPABASE_ANON_KEY);

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

Asupabase_url

BsupabaseUrl

CSUPABASE_URL_KEY

DSUPABASE_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using camelCase or lowercase names for environment variables.

Using a wrong or non-existent environment variable name.

Environment variables are case sensitive. The correct variable for the URL is SUPABASE_URL.

4fill in blank

hard

Fill both blanks to create a Supabase client with URL and anon key from environment variables.

Supabase

const supabase = createClient(process.env.[1], process.env.[2]);

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

ASUPABASE_URL

BSUPABASE_ANON_KEY

CSUPABASE_SERVICE_ROLE_KEY

DSUPABASE_API_KEY

Attempts:

3 left

💡 Hint

Common Mistakes

Using service role key instead of anon key.

Mixing up the order of URL and key.

The Supabase client requires the project URL and the anon key, both stored in environment variables SUPABASE_URL and SUPABASE_ANON_KEY.

5fill in blank

hard

Fill all three blanks to import, initialize, and export the Supabase client correctly.

Supabase

import { [1] } from '@supabase/supabase-js';

const supabaseUrl = process.env.[2];
const supabaseAnonKey = process.env.[3];

export const supabase = [1](supabaseUrl, supabaseAnonKey);

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

AcreateClient

BSUPABASE_URL

CSUPABASE_ANON_KEY

DsupabaseClient

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong import names.

Using incorrect environment variable names.

Trying to call a variable instead of the function.

You import createClient, then use environment variables SUPABASE_URL and SUPABASE_ANON_KEY to initialize the client.

Practice

1. What is the main purpose of initializing a Supabase client in your application?

easy

A. To connect your app to Supabase services using your project URL and key

B. To create a new Supabase project automatically

C. To deploy your app to the cloud

D. To generate API keys for other users

Solution

1. Step 1: Understand Supabase client role

   The Supabase client acts as the bridge between your app and Supabase backend services.

2. Step 2: Identify initialization purpose

   Initializing it with your project URL and key allows your app to securely communicate with your database and authentication services.

3. Final Answer:

   To connect your app to Supabase services using your project URL and key -> Option A

4. Quick Check:

   Supabase client connects app to services = C [OK]

Hint: Supabase client links app to backend using URL and key [OK]

Common Mistakes:

• Thinking initialization creates a new project
• Confusing client initialization with deployment
• Assuming keys are generated during initialization

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

easy

A. const supabase = new SupabaseClient('https://xyz.supabase.co', 'public-anon-key');

B. const supabase = createClient('https://xyz.supabase.co', 'public-anon-key');

C. const supabase = supabaseClient('https://xyz.supabase.co', 'public-anon-key');

D. const supabase = supabase.create('https://xyz.supabase.co', 'public-anon-key');

Solution

1. Step 1: Recall Supabase client initialization syntax

   The official method uses the function createClient with URL and key as arguments.

2. Step 2: Match correct syntax

   const supabase = createClient('https://xyz.supabase.co', 'public-anon-key'); matches the exact syntax: const supabase = createClient('URL', 'KEY');

3. Final Answer:

   const supabase = createClient('https://xyz.supabase.co', 'public-anon-key'); -> Option B

4. Quick Check:

   Use createClient(URL, KEY) = A [OK]

Hint: Use createClient() function with URL and key [OK]

Common Mistakes:

• Using new keyword with createClient
• Calling non-existent supabaseClient or supabase.create
• Mixing up function and class syntax

3. Given the following code snippet, what will be the output of console.log(supabaseUrl)?

const supabaseUrl = 'https://abc.supabase.co';
const supabaseKey = 'anon-key';
const supabase = createClient(supabaseUrl, supabaseKey);
console.log(supabaseUrl);

medium

A. 'https://abc.supabase.co'

B. undefined

C. An error because supabaseUrl is not defined

D. 'anon-key'

Solution

1. Step 1: Identify variable declaration

   supabaseUrl is declared as a constant string 'https://abc.supabase.co'.

2. Step 2: Understand console.log output

   Logging supabaseUrl prints its value, which is the URL string.

3. Final Answer:

   'https://abc.supabase.co' -> Option A

4. Quick Check:

   Logging declared string variable outputs string = D [OK]

Hint: Logging a declared variable prints its value [OK]

Common Mistakes:

• Confusing supabaseUrl with supabase client object
• Expecting error due to client initialization
• Mixing variable names

4. You wrote this code to initialize Supabase client but get an error:

const supabase = createClient(supabaseUrl, supabaseKey)

where supabaseUrl and supabaseKey are not defined anywhere. How do you fix it?

medium

A. Remove createClient and use new SupabaseClient() instead

B. Use environment variables directly inside createClient without defining them

C. Call createClient without any arguments

D. Define supabaseUrl and supabaseKey variables with your project URL and key before calling createClient

Solution

1. Step 1: Identify cause of error

   The error occurs because supabaseUrl and supabaseKey are used but never declared or assigned values.

2. Step 2: Fix by defining variables

   Assign your Supabase project URL and anon key to these variables before calling createClient.

3. Final Answer:

   Define supabaseUrl and supabaseKey variables with your project URL and key before calling createClient -> Option D

4. Quick Check:

   Variables must be defined before use = B [OK]

Hint: Always define variables before using them [OK]

Common Mistakes:

• Assuming createClient auto-defines variables
• Using wrong constructor syntax
• Ignoring variable declaration errors

5. You want to keep your Supabase keys secure and not expose them in your frontend code. Which is the best practice to initialize the Supabase client securely?

hard

A. Share your keys publicly so others can help debug

B. Hardcode the URL and key directly in your JavaScript files

C. Store the URL and key in environment variables and load them in your app during initialization

D. Use dummy keys in your app and replace them manually before deployment

Solution

1. Step 1: Understand security risks

   Hardcoding keys exposes them publicly, risking unauthorized access.

2. Step 2: Use environment variables

   Storing keys in environment variables keeps them out of source code and allows secure loading during app startup.

3. Final Answer:

   Store the URL and key in environment variables and load them in your app during initialization -> Option C

4. Quick Check:

   Environment variables secure keys = A [OK]

Hint: Use environment variables to keep keys secret [OK]

Common Mistakes:

• Hardcoding keys in frontend code
• Sharing keys publicly
• Using dummy keys without proper replacement