Typescript歧视的工会类型不被识别

我想基于在https://github.com/ngrx/example-app/找到的示例应用程序构建一个Angular 2/ngrx应用程序。我出口动作类型为区分联合Typescript歧视的工会类型不被识别

export const ActionTypes = { 
    QUERY: type('[Games] Query'), 
    QUERY_COMPLETE: type('[Games] Query Complete'), 
    INVALIDATE: type('[Games] Invalidate'), 
    SELECT: type('[Games] Select'), 
    LOAD_NEXT_PAGE: type('[Games] Load Next Page'), 
    LOAD_NEXT_PAGE_COMPLETE: type('[Games] Load Next Page Complete'), 

}; 

export class QueryAction implements Action { 
    type = ActionTypes.QUERY; 

    constructor(public payload: string) {} 
} 

export class QueryCompleteAction implements Action { 
    type = ActionTypes.QUERY_COMPLETE; 

    constructor(public payload: Game[]) {} 

} 

export class LoadNextPageCompleteAction implements Action { 
    type = ActionTypes.LOAD_NEXT_PAGE_COMPLETE; 

    constructor(public payload: Game[]) {} 
} 

export class LoadNextPageAction implements Action { 
    type = ActionTypes.LOAD_NEXT_PAGE; 

    constructor() {} 
} 

export class InvalidateAction implements Action { 
    type = ActionTypes.INVALIDATE; 

    constructor(){} 
} 

export class SelectAction implements Action { 
    type = ActionTypes.SELECT; 

    constructor(public payload: number) {} 
} 

export type Actions = QueryAction | QueryCompleteAction | InvalidateAction | SelectAction | LoadNextPageAction | LoadNextPageCompleteAction;

而且通过这些来减速功能，在辨别基于type属性如下：

export function reducer(state = initialState, action: game.Actions): State { 
    switch (action.type) { 
    case game.ActionTypes.LOAD_NEXT_PAGE: 
    case game.ActionTypes.QUERY: { 
     return Object.assign({}, state, {loading: true}); 
    } 
    case game.ActionTypes.QUERY_COMPLETE: { 
     return { 
     games: action.payload, 
     offset: action.payload.length, 
     loading: false, 
     selectedGameId: null 
     } 
    } 
    case game.ActionTypes.LOAD_NEXT_PAGE_COMPLETE: { 
     return { 
     games: [...state.games, ...action.payload], 
     offset: state.offset + action.payload.length, 
     loading: false, 
     selectedGameId: state.selectedGameId 
     } 
    } 
    case game.ActionTypes.SELECT: { 
     return Object.assign({}, state, {selectedGameId: action.payload}); 
    } 
    default: { 
     return state; 
    } 
    } 
}

这失败，出现错误编译（其他中错误）

Type 'string | number | Game[]' is not assignable to type 'Game[]'. 
Type 'string' is not assignable to type 'Game[]'. 
Property 'length' does not exist on type 'string | number | Game[]'. 
Property 'length' does not exist on type 'number'

我是否做错了或不了解歧视工会的工作方式？我的理解是，switch语句应该缩小可能的类型action.payload，以保证它是正确的类型。它似乎与联盟中所有成员的类型相比，而不是只有匹配类型的成员。

该项目使用的打字稿v2.1.6

来源

2017-02-20 rabble

您的代码看起来很好，与我使用ngrx示例一样。检查您的导入语句以查找“游戏”操作。确保它指向正确的操作文件。 –