/**
 * Installs dependencies in multiple package directories, handling npm workspace configuration.
 * Also supports adding new packages as dependencies in specific package directories.
 * Shows progress spinners and manages npm install execution with appropriate flags.
 *
 * @param packages - Optional array of package names to install
 * @param installLocations - Optional array of installation locations (defaults to all package locations in the project)
 * @param dev - Whether to add --save-dev flag (only when packages are specified)
 */
export declare function installPackages({ packages, installLocations, dev, }: {
    packages?: string[];
    installLocations?: string[];
    dev?: boolean;
}): Promise<void>;
export declare function updatePackages({ packages, installLocations, }: {
    packages?: string[];
    installLocations?: string[];
}): Promise<void>;
export declare function getProjectPackageJsonLocations(dir?: string, isUpdate?: boolean): Promise<string[]>;
export declare function isPackageInstalled(directory: string, packageName: string): boolean;
export declare function hasMissingPackages(directory: string): Promise<boolean>;