Update linking X flow

[dewabisma]

Summary

Created new endpoint for association X. This one will check if the user has the required mention in bio.

Endpoint

POST /addresses/associations/x

[n13]

Review for PR 49: Update linking X flow

Summary

This PR implements a new flow for linking an X (Twitter) account to a Quantus address. Instead of a direct link or OAuth, it verifies ownership by checking if the user's X bio contains a specific mention (configured as @QuantusNetwork).

Key Changes

1. Configuration (config/*.toml, src/config.rs)

• Added [x_association] section with a bio_mention setting.
• Updated Config struct to include XAssociationConfig.

2. Dependency Update (Cargo.toml)

• Bumped rusx to version 0.6.1.

3. New Handler (src/handlers/address.rs)

• Implemented associate_x_handle.
• Flow:
  1. Receives username in the request body.
  2. Fetches the Twitter user details (specifically description aka bio) using rusx.
  3. Verifies that the bio contains the configured bio_mention string.
  4. If verified, creates a new association in the database.
  5. Returns 204 No Content on success.

4. Routes (src/routes/address.rs)

• Added POST method to /addresses/associations/x endpoint.

5. Tests

• Added unit tests for the new handler:
  • test_associate_x_handle_success: Verifies correct association when bio matches.
  • test_associate_x_handle_fails_bad_bio: Verifies 401 Unauthorized when bio verification fails.
• Updated existing tests in other modules to include description in mock User objects.

Feedback

Positive

• Security: The "verify via bio" mechanism is a clever and simple way to prove ownership of the X account without requiring a complex OAuth integration for this specific use case.
• Code Structure: The implementation follows the existing pattern of handlers, services, and repositories well.
• Testing: Good coverage of the happy path and the verification failure case.

Suggestions / Questions

1. Case Sensitivity: The check !bio.contains(x_bio_mention) is case-sensitive.
   • Question: Should this be case-insensitive to be more user-friendly (e.g. if a user types @quantusnetwork instead of @QuantusNetwork)?
2. Duplicate Handling:
   • The handler calls state.db.x_associations.create. Ensure that the repository or database schema handles unique constraints (e.g., if one X account tries to link to multiple addresses, or one address to multiple X accounts) and that the error returned to the user is clear if a conflict occurs.
3. Rate Limiting:
   • Since this endpoint calls the Twitter API directly, ensure that associate_x_handle is protected by appropriate rate limits to prevent draining the API quota or abuse.

Conclusion

The PR looks solid and ready for merge, pending the minor considerations above.

Status: ✅ Approved (with non-blocking suggestions)

[n13]

LGTM, some suggestions above

Case sensitivity is probably a good one - just check they have quantus in lowercase of their bio (case ignored)