import { Factory, AttributeFunction, ArrayFactory } from "./index";
import { DiffProperties, ArrayElement } from "./utils";
import { DerivedFunction } from "./derive";
declare type Merge<Base, Result> = DiffProperties<Result, Base> & Partial<Base>;
declare type ExtendConfig<Base, Result> = {
    [Key in keyof Merge<Base, Result>]: Merge<Base, Result>[Key] | AttributeFunction<Merge<Base, Result>[Key]> | Factory<Merge<Base, Result>[Key]> | DerivedFunction<Result, Merge<Base, Result>[Key]> | ArrayFactory<ArrayElement<Merge<Base, Result>[Key]>>;
};
/**
 * Define a new factory function from an existing factory. The return value is a
 * function that can be invoked as many times as needed to create a given type
 * of object. Use the config param to define how the object is generated on each
 * invocation.
 *
 * @param base An existing factory to extend.
 * @param config An object that defines how the factory should generate objects.
 * Each key can either be a static value, a function that receives the
 * invocation count as the only parameter or another factory.
 */
declare function extend<Base, Result extends Base>(base: Factory<Base>, config: ExtendConfig<Base, Result>): Factory<Result>;
export { extend, ExtendConfig };