NestJS Mongo TypeError：this.memberModel不是构造函数

Question

我似乎无法在我的NestJS应用中找到此测试。按照用于连接NestJS & MongoDB的文档进行操作，我们在尝试运行createMember规范时收到以下屏幕截图中的错误。我也在下面添加了服务及其各自的规范。公共仓库是https://github.com/alobban/zeta-nestjs/tree/mongo/src/member。

非常感谢您的帮助。

import { Model } from 'mongoose';
import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';

import { Member } from './member.interface';
import { CreateMemberDto } from './dto/create-member-dto';

@Injectable()
export class MembersService {
  members = [
    { firstName: 'Jake', lastName: 'Miller', lineName: 'State Farm' },
  ];

  constructor(@InjectModel('Member') private readonly memberModel: Model<Member>) {}

  async getMembers(): Promise<Member[]> {
    return await this.memberModel.find().exec();
  }

  async createMember(createMemberDto: CreateMemberDto): Promise<Member> {
    const createdMember = new this.memberModel(createMemberDto);
    return await createdMember.save();
  }
}

import { Test } from '@nestjs/testing';
import { MongooseModule, getModelToken } from '@nestjs/mongoose';

import { MembersService } from './members.service';

const members = [
  { firstName: 'Jake', lastName: 'Miller', lineName: 'State Farm' },
];

describe('MembersService', () => {
  let membersService;

  beforeEach(async () => {
    const module = await Test.createTestingModule({
      providers: [
        MembersService,
        {
          provide: getModelToken('Member'),
          useValue: {
            find: jest.fn().mockReturnThis(),
            exec: jest.fn().mockResolvedValue(members),
          },
        },
      ],
    }).compile();

    membersService = await module.get<MembersService>(MembersService);
  });

  describe('getMembers', () => {
    it('calls getMembers and returns an array of Members', () => {
      expect(membersService.getMembers()).resolves.toEqual(members);
    });
  });

  describe('createMember', () => {
    it('calls membersService.createMember and returns result', async () => {
      const save = jest.fn().mockResolvedValue(true);

      expect(save).not.toHaveBeenCalled();
      const result = await membersService.createMember('newMember');

      expect(save).toHaveBeenCalled();
    });
  });
});