节点ts-jest spyOn方法与重载不匹配

// 假设有一个名为example的模块，其中包含了一个重载函数
// example.ts
export function foo(): string;
export function foo(num: number): number;
export function foo(arg?: number): string | number {
  if (typeof arg === 'number') {
    return arg * 2;
  }
  return 'foo';
}

// 在单元测试中使用jest.spyOn来模拟重载函数
// example.test.ts
import * as example from './example';

test('should return double of the input number', () => {
  const spy = jest.spyOn(example, 'foo');
  spy.mockReturnValue(10);

  const result = example.foo(5);

  expect(result).toBe(10);
  expect(spy).toHaveBeenCalledWith(5);

  spy.mockRestore();
});

test('should return "foo" if no argument is provided', () => {
  const spy = jest.spyOn(example, 'foo');
  spy.mockReturnValue('bar');

  const result = example.foo();

  expect(result).toBe('bar');
  expect(spy).toHaveBeenCalledWith();

  spy.mockRestore();
});