import type { OptionsSync } from 'cosmiconfig';
export interface FileLoaderOptions extends Partial<OptionsSync> {
    /**
     * basename of config file, defaults to `.env`.
     *
     * In other words, `.env.yaml`, `.env.yml`, `.env.json`, `.env.toml`, `.env.js`
     * will be searched by default.
     */
    basename?: string;
    /**
     * Use given file directly, instead of recursively searching in directory tree.
     */
    absolutePath?: string;
    /**
     * The directory to search from, defaults to `process.cwd()`. See: https://github.com/davidtheclark/cosmiconfig#explorersearch
     */
    searchFrom?: string;
    /**
     * If "true", ignore environment variable substitution.
     * Default: true
     */
    ignoreEnvironmentVariableSubstitution?: boolean;
    /**
     * If "true", disallow undefined environment variables.
     * Default: true
     */
    disallowUndefinedEnvironmentVariables?: boolean;
}
/**
 * File loader loads configuration with `cosmiconfig` from file system.
 *
 * It is designed to be easy to use by default:
 *  1. Searching for configuration file starts at `process.cwd()`, and continues
 *     to search up the directory tree until it finds some acceptable configuration.
 *  2. Various extensions are supported, such as `.json`, `.yaml`, `.toml`, `.js` and `.cjs`.
 *  3. Configuration base name defaults to .env (so the full name is `.env.json` or `.env.yaml`),
 *     separate file for each environment is also supported. For example, if current `NODE_ENV` is
 *     development, `.env.development.json` has higher priority over `.env.json`.
 *
 * @see https://github.com/davidtheclark/cosmiconfig
 * @param options cosmiconfig initialize options. See: https://github.com/davidtheclark/cosmiconfig#cosmiconfigoptions
 */
export declare const fileLoader: (options?: FileLoaderOptions) => (() => Record<string, any>);