/**
 * `unknown` is a distinct answer from `current`: without a successful check
 * clai must not claim the installation is up to date.
 */
export type UpdateState = "update-available" | "current" | "unknown" | "error";
export interface UpdateStatus {
    readonly state: UpdateState;
    readonly currentVersion: string;
    readonly latestVersion?: string | undefined;
    readonly updateAvailable: boolean;
    /** Why the state is unknown or errored. */
    readonly detail?: string | undefined;
}
export interface UpdatesPort {
    check(): Promise<UpdateStatus>;
}