blob: 362522877eae1b86742f72a492a7ebaeae3a826a [file] [log] [blame]
/**
* @license
* Copyright 2020 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import {IronOverlayBehavior} from '@polymer/iron-overlay-behavior/iron-overlay-behavior';
import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class';
import {PolymerElement} from '@polymer/polymer/polymer-element';
import {Constructor} from '../../utils/common-util';
// The mixinBehaviors clears all type information about superClass.
// As a workaround, we define IronOverlayMixin with correct type.
// Due to the following issues:
// https://github.com/microsoft/TypeScript/issues/15870
// https://github.com/microsoft/TypeScript/issues/9944
// we have to import IronOverlayBehavior in the same file where IronOverlayMixin
// is used. To ensure that this import can't be avoided, the second parameter
// is added. Usage example:
// class Element extends IronOverlayMixin(PolymerElement, IronOverlayBehavior as IronOverlayBehavior)
// The code 'IronOverlayBehavior as IronOverlayBehavior' required, because
// IronOverlayBehavior defined as an object, not as IronOverlayBehavior instance.
export const IronOverlayMixin = <T extends Constructor<PolymerElement>>(
superClass: T,
_: IronOverlayBehavior
): T & Constructor<IronOverlayBehavior> =>
// TODO(TS): mixinBehaviors in some lib is returning: `new () => T`
// instead which will fail the type check due to missing
// IronOverlayBehavior interface
// eslint-disable-next-line
mixinBehaviors([IronOverlayBehavior], superClass) as any;