Typescript 枚举键入错误（“字符串”类型的参数不可分配给类型参数）

Question

I have an enum define as follows:

export enum taskTypes {
  WORK = 'work',
  SLEEP = 'sleep',
  EXERCISE = 'exercise',
  EAT = 'eat'
}

On the top of my class I define the currentTask as follows:

private currentTask: string;

However, when I use the enums in [WORK, SLEEP].includes(currentTask) I get the following error.

Argument of type 'string' is not assignable to parameter of type 'currentTask'

The weird thing is when I simply just change it to use the actual string it doesn't complain.

['work', 'sleep'].includes(currentTask) ===> this works.

So what am I missing here?

Answer 1

currentTask is of type string, but WORK and SLEEP is enum members of type taskTypes

So [WORK, SLEEP] is an array of taskTypes enums. Such an array can never contain a string.

['work', 'sleep'] is an array of strings, which can contain a string.

If you type the private memeber to be of type taskTypes it will also work

private currentTask: taskTypes

Answer 2

Hi My case is similar and we are using strict mode in tsconfig,

--> my emun

export enum User {
    IMPLANTING = 'Imp',
    TREATING = 'Treate',
    CONSULTING = 'Guest'
}

In component Im importing this User emnum and trying to test the roles array

import {User} from './common.enum'
this.userRoles = User
let test = userRoles.includes(this.userRoles.IMPLANTING); 

// here im getting error as

argument of type 'any' is not assignable to parameter of type 'never'.

Can some one help

@KlasMellbourn #KlasMellbourn