import type { AddOn } from '@heroku/types/3.sdk';
import type { ResourceCtx } from '../../../core/extend-resource.js';
import type { UpgradeAddOnOptions } from './types.js';
/**
 * Change the plan of an add-on.
 *
 * Resolves the add-on first so the caller can pass any identifier
 * `resolveAddon` accepts. When `appIdentity` is provided, the resolve
 * is scoped to that app.
 *
 * If `plan` is unqualified (no `:`), it's prefixed with the resolved
 * add-on's `addon_service.name` — so callers can pass `hobby` rather
 * than `heroku-redis:hobby` if they don't already know the service.
 *
 * `options.onResolved` fires after the resolve and before the update,
 * receiving the resolved add-on. Useful for surfacing pre-update
 * state (the add-on's current plan, app, etc.) without an extra
 * round-trip.
 */
export declare function upgrade(ctx: Pick<ResourceCtx, 'platform'>, addonIdentity: string, plan: string, options?: UpgradeAddOnOptions): Promise<AddOn>;