resolveUser

resolveUser is a utility function or service component used to map a user reference to a single, canonical user record in a software system. It accepts a value that may represent the user in several forms and returns a normalized user object that can be used for authentication, authorization, and auditing.

Common input forms include numeric internal IDs, usernames, email addresses, external provider IDs, or session tokens. The resolver applies normalization, then queries the identity store in a defined order (for example by internal ID, then by username, then by email), and may apply additional disambiguation rules if multiple matches exist.

If a unique match is found, resolveUser returns the corresponding user record, typically containing fields such as id, username, displayName, email, roles, and metadata. If no match is found, it returns null or raises a not-found error. If multiple candidates exist, the function may return a list of candidates, or raise an ambiguity error requiring additional input to disambiguate.

In practice, resolveUser is used during login, profile fetches, access checks, and audit logging. Implementations may be synchronous or asynchronous, may integrate with databases or directory services, and often support caching and pluggable strategies. Security considerations include minimizing exposure of sensitive data and handling tokens securely. See also identity resolution, user management, authentication.