import { Extension } from 'handel-extension-api';
import { ExtensionDefinition, HandelCoreOptions, LoadedExtension } from '../datatypes';
import { NpmClient } from './npm';
import { ExtensionLoader } from './types';
export declare class NpmLoader implements ExtensionLoader {
    private readonly client;
    private readonly importer;
    constructor(client: NpmClient, importer: ModuleImporter);
    loadExtensions(definitions: ExtensionDefinition[], options: HandelCoreOptions, workingDirectory?: string, extensionsDirectory?: string): Promise<LoadedExtension[]>;
    private getInstallSpecs;
    private initExtensionsDir;
}
export declare type ModuleImporter = (path: string) => Promise<Extension>;
export declare function initNpmLoader(npmClient?: NpmClient, moduleImporter?: ModuleImporter): NpmLoader;