export type Logger = (...data: any[]) => void;
type LoggingFunction<T> = (value: T) => T;
/**
 * Logging the value between the promise chain.
 *
 * @return {Function<T>}
 * A value which pass through within a promise
 *
 * @example
 * Promise.resolve(3)
 *   .then(log())
 *   .then(doSomething)
 * // return 3 in a promise, after logging
 */
export default function log<T>(): LoggingFunction<T>;
/**
* Logging the value between the promise chain.
*
* @param {Function} [logger=console.log]
* - a logger; default would be console.log
*
* @return {Function<T>}
* A value which pass through within a promise
*
* @example
* Promise.resolve(true)
*   .then(log(console.warn))
*   .then(doSomething)
* // return true in a promise, after logging
*/
export default function log<T>(logger: Logger): LoggingFunction<T>;
/**
 * Logging the value between the promise chain.
 *
 * @param {Function} [logger=console.log]
 * - a logger; default would be console.log
 *
 * @param {*}
 * - additional arguments for logger
 *
 * @return {Function<T>}
 * A value which pass through within a promise
 *
 * @example
 * Promise.resolve('a')
 *   .then(log(console.log, "my value:"))
 *   .then(doSomething)
 * // return 'a' in a promise, after logging
 */
export default function log<T>(logger: Logger, ...args: any[]): LoggingFunction<T>;
export {};