如何解决"Type circularly references itself error"？

Question

以下是具有预期结果的问题示例：

const actionTypes = {
  name: {
    set: "name/set",
  },
} as const;

type ActionTypes = { [key: string]: (string | ActionTypes) }; //record value is string or ActionTypes

// "GetActionType" circularly references itself
type GetActionType<A extends ActionTypes> = A extends Record<
  string,
  infer Value
>
  ? Value extends string
    ? Value
    : GetActionType<Value> // "GetActionType" is not generic
  : unknown;

type SiteAction = GetActionType<typeof actionTypes>; // "GetActionType" is not generic
// expected to be 'name/set'

有没有办法在不运行出错的情况下完成此操作？

编辑

将 as const 添加到 actionTypes 的声明中，并在下面正确引用常量

TypeScript 版本 4.0.2

游乐场link.

Answer 1

以下应该有效：

与您的方法有两个主要区别：

翻转 Value extends string 到 Value extends ActionTypes 递归
标记为 siteActionTypes 到 as const 以推断特定类型

const siteActionTypes = {
  name: {
    set: 'name/set'
  }
} as const

type ActionTypes = { [key: string]: string | ActionTypes }

type GetActionType<A extends ActionTypes> = A extends Record<string, infer Value>
  ? Value extends ActionTypes
    ? GetActionType<Value>
    : Value
  : unknown

type SiteAction = GetActionType<typeof siteActionTypes>
// SiteAction has type 'name/set'

Typescript Playground

如何解决"Type circularly references itself error"？

How to resolve "Type circularly references itself error"?

circular-reference

typescript

编辑