Javascript 用Sinon存根类方法时出现的问题

我有一个具有以下类的NodeJS+Typescript应用程序：

export default class OrderStreamWriter {
  private readonly redis: IORedis;
  private readonly orderStream: string;
  private readonly logger: LoggerFactory;

  constructor(redisHost: string, redisPort: number, redisPass: string, orderStream: string) {
    this.orderStream = orderStream;

    this.redis = createRedisClient(redisHost, redisPort, redisPass);
    this.logger = new LoggerFactory('streams/OrderStreamWriter');
  }

  public async write(msg: string): Promise<void> {
    await this.redis.xadd(this.orderStream, '*', 'trade', msg).catch((err: Error) => {
      this.logger.log(
        `Error Writing message to stream (${this.orderStream}): ${err.message}. Quitting...`,
      );
      process.exit(1);
    });
  }
}

使用当前代码和注释行

const writesub=sinon.stub（OrderStreamWriter.prototype，“write”）我在运行测试时收到相同的错误：

TypeError:无法对不存在的属性进行存根写入

如何解决此问题？
请提供要测试的
TriggerContext
类的代码。是否确定导入测试文件并调用
ObjectStreamWriter
的对象是正确的对象？我注意到该类是其文件的默认导出。对于使用注释行的测试，您可以将
Writer
的定义更改为
class Writer{write（）{}
，并且给定的错误应该消失
// someclass.js

class SomeClass {
  prop1;
  prop2;
  contructor(param1, param2) {
    this.prop1 = param1;
    this.prop2 = param2;
  }

  async someFunction(givenParam) {
    // do something here

    return "somedata";
  }
}

// create a factory . This is what you will use to create an instance rather than using the new word ever time to create a new instance.

const someClassInstanceFactory = (param1, param2) => {
  return new SomeClass(param1, param2);
};

export default { someClassInstanceFactory, SomeClass };

// ********************************************************
// somemodule.js

// this file uses the class we created above as below

import classAndFactory from "./someclass.js";

const moduleFunction = () => {
  const instance = classAndFactory.someClassInstanceFactory(param1, param2);
  // this line returns an instance of SomeClass . it's like calling new SomeClass(pram1, param2);

  const result = instance.someFunction("givenParam");
  console.log(result);

  return result;
  // result should be 'somedata'

  // so how do we unit test moduleFunction and stub instance.someFunction when testing? ?
};

export default moduleFunction;

// *******************************************************************

// somemodule.test.js

import classAndFactory from "./../someclass.js";
import moduleFunction from "./somemodule.js";

const { someClassInstanceFactory, SomeClass } = classAndFactory;

// now if you want to stub any thing what you do is

describe("moduleFunction", () => {
  const fakeSomeClassInstance = new SomeClass(1, 2);

  // arrange

  // stub the factory first to return your fake instance created above.

  const expectedResut = "stubbed yoo";
  sinon
    .stub(classAndFactory, "someClassInstanceFactory")
    .returns(fakeSomeClassInstance);

  someFunctionStub = sinon
    .stub(fakeSomeClassInstance, "someFunction")
    .returns(expectedResut);

  it("must call someFunction function with required argument", () => {
    // act

    const result = moduleFunction();

    // assert
    sinon.assert.calledOnce(someFunctionStub);
    assert.equals(result, expectedResut);
  });
});


// someclass.js

class SomeClass {
  prop1;
  prop2;
  contructor(param1, param2) {
    this.prop1 = param1;
    this.prop2 = param2;
  }

  async someFunction(givenParam) {
    // do something here

    return "somedata";
  }
}

// create a factory . This is what you will use to create an instance rather than using the new word ever time to create a new instance.

const someClassInstanceFactory = (param1, param2) => {
  return new SomeClass(param1, param2);
};

export default { someClassInstanceFactory, SomeClass };

// ********************************************************
// somemodule.js

// this file uses the class we created above as below

import classAndFactory from "./someclass.js";

const moduleFunction = () => {
  const instance = classAndFactory.someClassInstanceFactory(param1, param2);
  // this line returns an instance of SomeClass . it's like calling new SomeClass(pram1, param2);

  const result = instance.someFunction("givenParam");
  console.log(result);

  return result;
  // result should be 'somedata'

  // so how do we unit test moduleFunction and stub instance.someFunction when testing? ?
};

export default moduleFunction;

// *******************************************************************

// somemodule.test.js

import classAndFactory from "./../someclass.js";
import moduleFunction from "./somemodule.js";

const { someClassInstanceFactory, SomeClass } = classAndFactory;

// now if you want to stub any thing what you do is

describe("moduleFunction", () => {
  const fakeSomeClassInstance = new SomeClass(1, 2);

  // arrange

  // stub the factory first to return your fake instance created above.

  const expectedResut = "stubbed yoo";
  sinon
    .stub(classAndFactory, "someClassInstanceFactory")
    .returns(fakeSomeClassInstance);

  someFunctionStub = sinon
    .stub(fakeSomeClassInstance, "someFunction")
    .returns(expectedResut);

  it("must call someFunction function with required argument", () => {
    // act

    const result = moduleFunction();

    // assert
    sinon.assert.calledOnce(someFunctionStub);
    assert.equals(result, expectedResut);
  });
});