import { Project, ResolveOptions, Resolver, Descriptor, Package, Report, Cache } from '@yarnpkg/core';
import { Fetcher, FetchOptions } from '@yarnpkg/core';
export type PackageUpdate = {
    descriptor: Descriptor;
    currentPackage: Package;
    updatedPackage: Package;
    resolvedPackage: Package;
};
export type Algorithm = (project: Project, patterns: Array<string>, opts: {
    resolver: Resolver;
    resolveOptions: ResolveOptions;
    fetcher: Fetcher;
    fetchOptions: FetchOptions;
}) => Promise<Array<Promise<PackageUpdate>>>;
export declare enum Strategy {
    /**
     * This strategy dedupes a locator to the best candidate already installed in the project.
     *
     * Because of this, it's guaranteed that:
     * - it never takes more than a single pass to dedupe all dependencies
     * - dependencies are never downgraded
     */
    HIGHEST = "highest"
}
export declare const acceptedStrategies: Set<Strategy.HIGHEST>;
export type DedupeOptions = {
    strategy: Strategy;
    patterns: Array<string>;
    cache: Cache;
    report: Report;
};
export declare function dedupe(project: Project, { strategy, patterns, cache, report }: DedupeOptions): Promise<number>;