Typescript:从值中引用泛型类型以用作其他地方的类型

Question

代码如下：

// file1.ts
interface X { ... } // Don't want to directly export this (private/internal)

// Assume LibInterface<T> is some random interface from an external library
export const func: (arg: LibInterface<X> => string) = ...;


// file2.ts (essentially the jest test file)
import { func } from './file1';

const x: X = ...;
const arg: LibInterface<X> = ...;

expect(func(arg)).toEqual(...);

在上面的例子中，我如何引用第二个文件中的X类型？

使用X和jest-mock-extended类型的复杂用例：const mockX = mock<X>(...);

我已经搜索过了，也在https://www.typescriptlang.org/docs/handbook/utility-types.htmlhttps://www.typescriptlang.org/docs/handbook/utility-types.html上找过了，但还是找到了解决方案。

Answer 1

您是否能够将泛型类型添加到函数中？应该是这样的：

// file1.ts
interface X { ... } // Don't want to directly export this (private/internal)

// Assume LibInterface<T> is some random interface from an external library
export const func: <T extends X = X>(arg: LibInterface<T> => string) = ...;


// file2.ts (essentially the jest test file)
import { func } from './file1';

const x: X = ...;
const arg: LibInterface<X> = ...;

expect(func(arg)).toEqual(...);