typescript 如何将泛型类型的键约束为仅字符串

Question

我想要一个通用类型OnlyStringKey<T>如下所示。

   //This line has no compile errors
    let x: OnlyStringKey<{whatEverJustString1: 1, whatEverJustString2: '' }>;
    
    //This line has error. Because key 2 is a number but a string
    let x: OnlyStringKey<{whatEverJustString1: 1, 2: '' }>;
    
    //This line has error too. Because key symbol.search is symbole but a string
    let x: OnlyStringKey<{whatEverJustString1: 1, [Symbol.search]: '' }>;

我尝试了几种方法。 而且它们都不起作用

Answer 1

您可以将以下约束添加到OnlyStringKey ：

type OnlyStringKey<
  T extends Record<string, any> & Record<number | symbol, never> 
> = T

这将确保所有number和symbol键只能具有never类型。

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操场

Answer 2

我不认为类型可以同时受到约束和通用，但您可能想要OnlyStringKey: Record<string, any> or OnlyStringKey:{ [key: string]: any }