fix(auth-server): safely access metrics methods in redis

[sreecharan-desu]

Fixes #16491. This PR updates the Redis wrapper in to safely access metrics methods (, ) using optional chaining (). This prevents crashes (e.g., ) when the metrics object is undefined or mocked incompletely, such as in certain test environments or when metrics are disabled via configuration.

[dschom]

Fixes #16491. This PR updates the Redis wrapper in to safely access metrics methods (, ) using optional chaining (). This prevents crashes (e.g., ) when the metrics object is undefined or mocked incompletely, such as in certain test environments or when metrics are disabled via configuration.

Thank you for this contribution! We'd like to request that the mocks are fixed instead of using optional chaining. Although this.metrics is optional, we don't want to mask an incorrect instantiation or mock by making the methods themselves optional.

[sreecharan-desu]

Thanks for the feedback! Reverted the optional chaining on methods and fixed the mock injection in instead. this.metrics is now properly instantiated with mocks.

[sreecharan-desu]

Tests for Redis metrics implementation are passing locally with Docker:

        ✔ removes all tokens for the user
        ✔ does nothing for nonexistent users
        ✔ does nothing for nonexistent clients
    Refresh Token Metadata
      setRefreshToken
        ✔ sets expiry
        ✔ prunes old tokens
        ✔ maxes out at 20 recent tokens

  Redis down
    touchSessionToken
      ✔ returns without error
    getSessionTokens
      ✔ returns an empty object without error
    pruneSessionTokens
      ✔ throws a timeout error


  43 passing (191ms)