我可以将字符串字面类型用于句法糖吗？

Question

我可以使用字面类型给用户一些建议，但没有剥夺他使用自定义字符串，我尝试了：

type  fooType = string | 'suggestions-1' | 'suggestions-2';

我也尝试使用字符串类，因此它似乎有效，但对我的目的不利，

type fooType = String | 'suggestions-1' | 'suggestions-2';

我在此< a href="https://www.typescriptlang.org/play?#code/FAFwngDgpgBAyiATgSwHYHMAqlYF4YDOSa6MAPjAOQECu66URyA9qgQLQCMl5Vt9jECzbsATJQDcMAPTSYAHlz4iKDDHDRgoHPGIYAwgBsAhgQIx8CVaQrU6DJqw7dedgY5HipMuYst7SAGMTMy1taBgAUQAPYwBbCEM8GABvYBgMmAhjVChDI1MCAC5da2xoCWAAX0rApxAYVGY4e0FhYqjYhKSLVPTM7Nz8kI6AIkCaImY40Z8FJRhMAAtYAEkAEUiYABNmRuYG-gcGt2P2rh5bI7anMUpqyq0NWBj4xKhRXrTMrJy8grMJSsJABBEqNWAdTYDQA7sgQEsWu4hE4Sq9uh8vv0MoN-iMSuNJiBpjAAEY0Q6tIizWTzfDLNabQhUk7XDzOS58FnncRkikwYyGAh7OEIgUwABmiCgsECS2YyECUAeYTQICgiAlxiVMFWqHVmu1UAAYohpgAZZCkxDGRBgPo-XHDQolFQkapaWkI2WsCXIUhoGBQaIG1CCnbIQXMUjSgjQQINb26-UarVK00Wq02u0wIqQ+rqFYABTNpKScRKeoNaZNZriluttvt+FFiO5TiknrkUL9AdQQZDGrDhgjUZjjHjiZWyerRoz9azTbzUKIAsrKcN6brDezzf2SLOTiAA" rel="nofollow noreferrer">TypeScript playground

Answer 1

type StringAndOthers<T> = T | (string & Record<never, never>);
type FooType = StringAndOthers<"suggestions-1" | "suggestions-2">;

const suggestion: FooType = 'suggestions-1';
const suggestion1: FooType = 'suggestions-2';
const suggestion3: FooType = 'suggestions-4';

Answer 2

我认为一种更好的方法是首先声明枚举

export enum abc {
    a = 'A',
    b = 'B'
   }

，然后声明您的类型：

a:abc|string 

在分配时可能使用ABC的值而不是输入字符串