无法在nestjs中模拟elasticsearch服务

Question

当前行为

Nest can't resolve dependencies of the ElasticsearchService (?). Please make sure that the argument at index [0] is available in the ElasticsearchModule context.

预期行为

在测试模块中创建ElasticSearchService

带指令的问题的最小再现

import { Test, TestingModule } from '@nestjs/testing';
import { RepliesController } from './replies.controller';
import { ElasticsearchService, ElasticsearchModule } from '@nestjs/elasticsearch';
import { Client } from 'elasticsearch';

describe('Replies Controller', () => {
  let module: TestingModule;
  let elasticsearch: ElasticsearchService;

  beforeAll(async () => {
    module = await Test.createTestingModule({
      imports: [ElasticsearchModule],
      controllers: [RepliesController],
      components: [ElasticsearchService, {provide: Client, useValue: {}}],
    }).compile();

    elasticsearch = module.get<ElasticsearchService>(ElasticsearchService);
  });
  it('should be defined', () => {
    const controller: RepliesController = module.get<RepliesController>(RepliesController);
    expect(controller).toBeDefined();
  });
});

环境

   [Nest Information]
elasticsearch version : 0.1.2
common version        : 5.4.0
core version          : 5.4.0

Answer 1

您需要使用测试模块公开的方法来覆盖提供程序，而不是在组件数组中这样做：

beforeAll(async () => {
    module = await Test.createTestingModule({
      imports: [ElasticsearchModule],
      controllers: [RepliesController]
    })
    .overrideProvider(ElasticsearchService)
    .useValue(/* your mock or whatever */)
    .compile();

在测试部分的NestJs文档中有这方面的例子。