Typescript 无法检查传递给Jest模拟对象的参数

我有一个相当直接的Typescript类和方法。我想使用Jest测试此方法以模拟此方法的依赖关系：

import {DynamoWorkflow} from '..';
import {Injectable} from '@nestjs/common';

@Injectable()
export class PipelineService {
    getCoverageByServiceName(serviceName: string): Promise<QueryResult<PipelineEvent>> {
        return new DynamoWorkflow().queryPipelineEvents(serviceName);
    }
}

这段代码不会编译。消息是

类型“（serviceName:string）=>Promise.ts（2339）

上不存在属性“mock”

我犯了错误的代码块

我尝试了

expect（mockDynamo.queryPipelineEvents）但这也不会编译，错误是：
类型“MockedObjectDeep”上不存在属性“queryPipelineEvents”。ts（2339）

我还尝试了
expect（mockDynamo.mock.instances[0].queryPipelineEvents）.toBeCalledWith（methodArg）。它编译和运行正常，但失败，并显示以下消息：

    expect(received).toBeCalledWith(...expected)

    Matcher error: received value must be a mock or spy function

    Received has value: undefined

      44 |     // expect(mockedDynamoMethod.mock.calls[0][0]).toHaveBeenCalledWith(methodArg);
      45 |     // expect(mockDynamo.queryPipelineEvents).toBeCalledWith(methodArg);
    > 46 |     expect(mockDynamo.mock.instances[0].queryPipelineEvents).toBeCalledWith(methodArg);
         |                                                              ^
      47 | 
      48 |     // Test #3: confirm the result is what we expect
      49 |     expect(actualResult).resolves.toEqual(mockQueryResult);


有人能帮助我理解如何确认模拟方法的参数与预期一致吗？
一位同事正在进行不同的测试，并意外地找到了答案。关键是将mock方法分配给被模拟的对象和方法。扔掉原始代码中的所有模拟，并将其替换为以下内容：

jest.mock('../../../../workflows/dynamoworkflow');
const mockMethod = jest.fn();
mockMethod.mockReturnValue(Promise.resolve(mockQueryResult));
DynamoWorkflow.prototype.queryPipelineEvents = mockMethod; //<- key here!

jest.mock('../../../../workflows/dynamoworkflow');
const mockMethod = jest.fn();
mockMethod.mockReturnValue(Promise.resolve(mockQueryResult));
DynamoWorkflow.prototype.queryPipelineEvents = mockMethod; //<- key here!

describe("PipelineService", () => {

  it("getCoverageByServiceName returns same data as db supplies", () => {
    //setup mock data...
    const mockPipelineEvent: PipelineEvent = new PipelineEvent();
    mockPipelineEvent.aut = "fake data";
    const mockPipelineEvents: PipelineEvent[] = [mockPipelineEvent];
    const mockQueryResult = {results: mockPipelineEvents, total: 1};

    //setup mock...
    jest.mock('../../../../workflows/dynamoworkflow');
    const mockMethod = jest.fn();
    mockMethod.mockReturnValue(Promise.resolve(mockQueryResult));
    DynamoWorkflow.prototype.queryPipelineEvents = mockMethod;

    //exercise the method we're testing...
    const methodArg = "foo-service";
    const serviceUnderTest = new PipelineService();
    const actualResult = serviceUnderTest.getCoverageByServiceName(methodArg);

    // and test...
    expect(mockMethod).toHaveBeenCalledWith(methodArg);
    expect(actualResult).resolves.toEqual(mockQueryResult);
  });

})