Common rule patterns in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to allow read access only to authenticated users.

Firebase

allow read: if request.auth [1] null;

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

A<

B==

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '!=' causes the rule to allow only unauthenticated users.

Using comparison operators like '<' or '>' is invalid here.

The rule checks that the user is authenticated by ensuring request.auth is not null.

2fill in blank

medium

Complete the code to allow write access only if the user's UID matches the document ID.

Firebase

allow write: if request.auth.uid [1] resource.id;

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

A==

B!=

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' allows users to write to documents not matching their UID.

Using '<=' or '>' is not meaningful for string comparison here.

This rule ensures users can only write to documents that match their own UID.

3fill in blank

hard

Fix the error in the rule that allows read access only if the user is authenticated and the document is public.

Firebase

allow read: if request.auth [1] null && resource.data.public == true;

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

A===

B!=

C==

D!==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' allows unauthenticated users to read.

Using strict equality operators like '===' is not supported in Firebase rules.

The rule must check that request.auth is not null to confirm authentication.

4fill in blank

hard

Fill both blanks to allow update only if the user is authenticated and the new data has a 'status' field equal to 'active'.

Firebase

allow update: if request.auth [1] null && request.resource.data.status [2] 'active';

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

A!=

B==

C===

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' for authentication check allows unauthenticated users.

Using '===' causes syntax errors in Firebase rules.

The rule checks that the user is authenticated and the new data's status is exactly 'active'.

5fill in blank

hard

Fill all three blanks to allow delete only if the user is authenticated, the document owner matches the user, and the document is not locked.

Firebase

allow delete: if request.auth.uid [1] resource.data.owner && request.auth [2] null && resource.data.locked [3] false;

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

A==

B!=

D!

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up operators causes the rule to allow unauthorized deletes.

Checking locked with '!=' false would allow locked documents to be deleted.

The rule ensures the user owns the document, is authenticated, and the document is unlocked before allowing deletion.