/**
 * Parts of this file come from the official config module for Nest.js
 *
 * @see https://github.com/nestjs/config/blob/master/lib/config.module.ts
 */
export interface DotenvLoaderOptions {
    /**
     * If set, use the separator to parse environment variables to objects.
     *
     * @example
     *
     * ```bash
     * app__port=8080
     * db__host=127.0.0.1
     * db__port=3000
     * ```
     *
     * if `separator` is set to `__`, environment variables above will be parsed as:
     *
     * ```json
     * {
     *     "app": {
     *         "port": 8080
     *     },
     *     "db": {
     *         "host": "127.0.0.1",
     *         "port": 3000
     *     }
     * }
     * ```
     */
    separator?: string;
    /**
     * If set, this function will transform all environment variable keys prior to parsing.
     *
     * Be aware: If you transform multiple keys to the same value only one will remain!
     *
     * @example
     *
     * .env file: `PORT=8080` and `keyTransformer: key => key.toLowerCase()` results in `{"port": 8080}`
     *
     * @param key environment variable key
     */
    keyTransformer?: (key: string) => string;
    /**
     * If "true", environment files (`.env`) will be ignored.
     */
    ignoreEnvFile?: boolean;
    /**
     * If "true", predefined environment variables will not be validated.
     */
    ignoreEnvVars?: boolean;
    /**
     * Path to the environment file(s) to be loaded.
     */
    envFilePath?: string | string[];
    /**
     * A boolean value indicating the use of expanded variables.
     * If .env contains expanded variables, they'll only be parsed if
     * this property is set to true.
     *
     * Internally, dotenv-expand is used to expand variables.
     */
    expandVariables?: boolean;
    /**
     * If "true", already defined environment variables will be overwritten.
     */
    overrideEnvVars?: boolean;
}
/**
 * Dotenv loader loads configuration with `dotenv`.
 *
 */
export declare const dotenvLoader: (options?: DotenvLoaderOptions) => () => Record<string, any>;