[英]Typescript: enum generic Type as parameter to function
i have a function which takes two parameters one is a key and other is an enum type.我有一个函数,它接受两个参数,一个是键,另一个是枚举类型。 I am trying to generalize this function with strong typing to take any enum type and return the value:我试图用强类型来概括这个函数来获取任何枚举类型并返回值:
export const getStatus = <T>(key: string, statEnum: any): string => {
return statEnum(key);
}
function call:函数调用:
console.log(getStatus<SVC_A>('AUTH_122', SVC_A));
This above function works with paramater typed as any statEnum: any
but if I change it to statEnum: typeof T
it throws an error message上面的函数适用于任何statEnum: any
但如果我将其更改为statEnum: typeof T
它会引发错误消息
T only refers to a type, but is being used as a value here T 仅指一种类型,但在这里用作值
Parameter typing works if I add in a variable如果我添加变量,参数输入有效
type supportedEnums = typeof SVC_A | typeof SVC_B
export const getStatus = <T>(key: string, statEnum: supportedEnums): string => {
return statEnum(key);
}
curious to understand, why it works with supportedEnums type but when it's added as typeof T
it doesn't.很好奇,为什么它适用于 supportedEnums 类型,但是当它添加为typeof T
时却没有。
i also tried it as我也试过了
export const getStatus = <T>(key: string, statEnum: T): string => {
return statEnum(key);
}
updated function parameter type to T statEnum: T
it thorws error message while calling the function function call:将函数参数类型更新为 T statEnum: T
它在调用函数函数调用时抛出错误消息:
console.log(getStatus<SVC_A>('AUTH_122', SVC_A));
Argument of type 'typeof SVC_A' is not assignable to parameter of type 'SVC_A' “typeof SVC_A”类型的参数不可分配给“SVC_A”类型的参数
Is there a possibility to define an enum as a parameter and typesafe?是否有可能将枚举定义为参数和类型安全?
First of all, you dont need to use explicit generic parameter.首先,您不需要使用显式泛型参数。 Consider this example:考虑这个例子:
enum SVC_A {
INVALID = 'INVALID',
YENNA = 'YENNA',
AUTH_122 = 'AUTH FAILED',
}
type PseudoEnum = Record<string | number, string | number>
function getStatus<Enum extends PseudoEnum, Key extends keyof Enum>(statEnum: Enum, key: Key) {
return statEnum[key];
};
const foo = getStatus(SVC_A, 'YENNA') // SVC_A.YENNA
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