/**

* @license

* Copyright Google LLC All Rights Reserved.

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

import {Type} from '../interface/type';

import {stringify} from '../util/stringify';

import {NG_FACTORY_DEF} from './fields';

/**

* Definition of what a factory function should look like.

*/

export type FactoryFn<T> = {

/**

* Subclasses without an explicit constructor call through to the factory of their base

* definition, providing it with their own constructor to instantiate.

*/

<U extends T>(t?: Type<U>): U;

/**

* If no constructor to instantiate is provided, an instance of type T itself is created.

*/

(t?: undefined): T;

};

export function getFactoryDef<T>(type: any, throwNotFound: true): FactoryFn<T>;

export function getFactoryDef<T>(type: any): FactoryFn<T> | null;

export function getFactoryDef<T>(type: any, throwNotFound?: boolean): FactoryFn<T> | null {

const hasFactoryDef = type.hasOwnProperty(NG_FACTORY_DEF);

if (!hasFactoryDef && throwNotFound === true && ngDevMode) {

throw new Error(`Type ${stringify(type)} does not have 'ɵfac' property.`);

}

return hasFactoryDef ? type[NG_FACTORY_DEF] : null;

}