[Solved] Given this guard code, what will canActivate return when the user role is 'admin'? class RoleGuard implements CanActivate { canActivate(context:... return request.user?.role === 'admin'; | NestJS

NestJS - Guards

Given this guard code, what will canActivate return when the user role is 'admin'?

class RoleGuard implements CanActivate {
  canActivate(context: ExecutionContext): boolean {
    const request = context.switchToHttp().getRequest();
    return request.user?.role === 'admin';
  }
}

AAlways true

Btrue if user role is 'admin', false otherwise

CAlways false

DThrows an error if user is undefined

Step-by-Step Solution

Solution:

Step 1: Analyze the return condition
The method returns true only if request.user?.role equals 'admin'.
Step 2: Understand optional chaining effect
If user is undefined, optional chaining returns undefined, so the comparison is false.
Final Answer:
Returns true if role is 'admin', else false -> Option B
Quick Check:
Role check returns true only for 'admin' [OK]

Quick Trick: Optional chaining prevents errors if user is missing [OK]

Common Mistakes:

Assuming always true
Assuming always false
Expecting error when user is undefined

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Given this guard code, what will canActivate return when the user role is 'admin'?

Step 1: Analyze the return condition

Step 2: Understand optional chaining effect

Final Answer:

Quick Check:

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