Jest用不同的参数模拟同一个函数两次

// fetchUser.js
export const fetchUser = (userId) => {
  // 实际实现会调用外部服务
};

// userData.js
import { fetchUser } from './fetchUser';

export const getUserData = (userId) => {
  return fetchUser(userId).then(data => {
    return { id: data.id, name: data.name };
  });
};

// userData.test.js
import { getUserData } from './userData';
import * as fetchUserModule from './fetchUser';

jest.mock('./fetchUser');

describe('getUserData', () => {
  it('should return user data for a valid user ID', async () => {
    fetchUserModule.fetchUser.mockResolvedValue({ id: 1, name: 'John Doe' });
    const result = await getUserData(1);
    expect(result).toEqual({ id: 1, name: 'John Doe' });
  });

  it('should handle errors for an invalid user ID', async () => {
    fetchUserModule.fetchUser.mockRejectedValue(new Error('User not found'));
    await expect(getUserData(999)).rejects.toThrow('User not found');
  });
});

it('should handle different user IDs correctly', async () => {
  fetchUserModule.fetchUser.mockImplementation((userId) => {
    if (userId === 1) {
      return Promise.resolve({ id: 1, name: 'John Doe' });
    } else if (userId === 2) {
      return Promise.resolve({ id: 2, name: 'Jane Doe' });
    } else {
      return Promise.reject(new Error('User not found'));
    }
  });

  const result1 = await getUserData(1);
  expect(result1).toEqual({ id: 1, name: 'John Doe' });

  const result2 = await getUserData(2);
  expect(result2).toEqual({ id: 2, name: 'Jane Doe' });

  await expect(getUserData(999)).rejects.toThrow('User not found');
});