Fix: Implement Validate Method in ZitadelStrategy

[EngineerNV]

Fix: Implement PassportStrategy's Abstract validate Method in ZitadelStrategy

Problem:

When a developer tries to run the server with npm run start:dev - they run into an exception error
ERROR in ./libs/zitadel-auth/src/strategy/zitadel.strategy.ts:9:14
TS2515: Non-abstract class 'ZitadelStrategy' does not implement inherited abstract member validate from class 'ZitadelIntrospectionStrategy & PassportStrategyMixin'.

`     7 `|`
     8 | @Injectable()
  >  9 | export class ZitadelStrategy extends PassportStrategy(
       |              ^^^^^^^^^^^^^^^
    10 |   ZitadelIntrospectionStrategy,
    11 |   'zitadel',
    12 | ) {

Solution:

This patch addresses a critical requirement by implementing the abstract validate method within the ZitadelStrategy class. The validate method is mandated by the PassportStrategyMixin abstract class, which is part of the @nestjs/passport library. By implementing this method, we ensure that our Zitadel authentication strategy correctly adheres to the Passport framework's expected structure and lifecycle.

Currently, the implemented validate method performs a minimal operation: it receives the user payload (of type ZitadelUser) and returns it without modification. This provides a functional baseline that satisfies the abstract method's requirement.

Changes:

• Implemented the validate method in zitadel.strategy.ts, fulfilling the abstract method requirement from PassportStrategyMixin.

Rationale:

The validate method serves as the hook for processing and validating user information retrieved from the authentication provider (in this case, ZITADEL). By implementing this method, we gain the ability to:

• Transform the user data into a format suitable for our application.
• Perform custom validation checks to ensure the user meets specific criteria.
• Enrich the user object with additional information from other data sources (e.g., a database).

This initial implementation provides a necessary foundation for future enhancements to the Zitadel authentication strategy.

Next Steps:

• Review the current implementation to ensure it aligns with the project's coding standards and security best practices.
• Evaluate the need for custom validation logic or user enrichment within the validate method based on application requirements.

[tafaust]

Thanks for the contribution!