/**
 * `common/test-helper.ts`
 * - helper functions for test
 *
 *
 * @author      Steve Jung <steve@lemoncloud.io>
 * @date        2019-10-16 initial version
 *
 * @copyright (C) 2019 LemonCloud Co Ltd. - All Rights Reserved.
 */
/**
 * catch error as string
 *
 * ```js
 * const a = sync () => throw new Error('ERROR');
 * expect(await a().catch(GETERR)).toEqual('ERROR');
 * ```
 * @param e
 */
export declare const GETERR: (e: any) => string;
/**
 * catch error as { error: string }
 *
 * ```js
 * const a = sync () => throw new Error('ERROR');
 * expect(await a().catch(GETERR$)).toEqual({ error:'ERROR' })
 * ```
 * @param e
 */
export declare const GETERR$: (e: any) => {
    error: string;
};
/**
 * return null if 404 not found.
 * @param e error
 */
export declare const NUL404: (e: Error) => any;
/**
 * improve expect() function with projection field.
 *
 * @param test      function or data.
 * @param view      projection attributes.
 */
export declare const expect2: (test: any, view?: string) => any;
/**
 * ignore of `it()`
 *
 * @param name
 * @param callback
 */
export declare const _it: (name: string, callback?: (done?: any) => any) => void;
/**
 * use `target` as value or environment value.
 * environ('PROFILE', 'none') => use env.PROFILE if exist, or 'none'
 */
export declare const environ: (envName: string, envValue?: string) => string;
/**
 * filter function()
 */
export interface Filter<T> {
    (name: string, val: any, thiz?: any, attr?: string | number): T;
}
/**
 * marshaler: convert object to dotted list.
 *
 * @param obj   json object
 * @param name  current name
 * @param list  result list
 * @param filter filter function.
 */
export declare const marshal: <T>(obj: any, filter: Filter<T>, name?: string, list?: T[], thiz?: any, attr?: string | number) => T[];
/**
 * wait for some time (in msec).
 *
 * ```js
 * await waited();
 * ``
 * @param t msec
 */
export declare const waited: (t?: number) => Promise<unknown>;