“IPromise<any>”不可分配给类型“Promise<any>”

Question

我正在为用户更改选项卡时构建一个确认对话框。该代码工作正常，但tslint抱怨类型不匹配。控制器看起来像：

export class MyController implements ng.IController {

    constructor(private $transitions: TransitionService,
                private $translate: angular.translate.ITranslateService) {
        'ngInject';

        $transitions.onStart({}, () =>
            this.alert
                .showConfirm(
                    this.$translate.instant('dialogs.confirmLeave.content'),
                    this.$translate.instant('dialogs.confirmLeave.title')
                )
                .then(() => true)
                .catch(() => false)
        );
    }

    ...
}

this.alert.showConfirmthis.$uibModal.open()最终从 angular-ui-bootstrap调用。这会给出以下警告：

error TS2345: Argument of type '() => IPromise<boolean>' is not assignable to parameter of type 'TransitionHookFn'.
  Type 'IPromise<boolean>' is not assignable to type 'boolean | void | TargetState | Promise<boolean | void | TargetState>'.
    Type 'IPromise<boolean>' is not assignable to type 'Promise<boolean | void | TargetState>'.
      Types of property 'then' are incompatible.
        Type '{ <TResult>(successCallback: (promiseValue: boolean) => TResult | IPromise<TResult>, errorCallbac...' is not assignable to type '<TResult1 = boolean | void | TargetState, TResult2 = never>(onfulfilled?: (value: boolean | void ...'.
          Type 'IPromise<any>' is not assignable to type 'Promise<any>'.
            Types of property 'then' are incompatible.
              Type '{ <TResult>(successCallback: (promiseValue: any) => TResult | IPromise<TResult>, errorCallback?: ...' is not assignable to type '<TResult1 = any, TResult2 = never>(onfulfilled?: (value: any) => TResult1 | PromiseLike<TResult1>...'.
                Type 'IPromise<any>' is not assignable to type 'Promise<any>'.

有想法该怎么解决这个吗？

Answer 1

看起来无论this.alert.showConfirm()是什么，它都没有返回真实的Promise. 尝试将结果包装在Promise：

export class MyController implements ng.IController {

    constructor(private $transitions: TransitionService,
                private $translate: angular.translate.ITranslateService) {
        'ngInject';

        $transitions.onStart({}, () =>
            Promise.resolve(
                this.alert
                    .showConfirm(
                        this.$translate.instant('einsteinsst.dialogs.confirmLeave.content'),
                        this.$translate.instant('einsteinsst.dialogs.confirmLeave.title')
                    )
            )
            .then(() => true)
            .catch(() => false)
        );
    }

    ...
}

Promise.resolve()将转换任何 thenable （即任何实现IPromise为真正的Promise，但IPromise接口不直接兼容Promise。有关更多详细信息，

请参阅文档。