Javascript 为什么不调用我的Jest 模拟函数实现

对于我收集的AWS JS Node lambdas，我有以下JEST测试配置.我有一个名为dynamoStore的模块，我在几个不同的lambdas Package.json中引用并在lambdas中使用.我正试图通过模拟调用DynamoDB的发电机存储模块来测试这些lambdas中的一个.问题是jest.fn实现永远不会被调用.我通过在该行中插入断点以及记录调用方法从该行返回的值来确认这一点.

当我在调试器中判断lambda1/index.js时，getVehicleMetaKeysFromDeviceId()是一个JEST对象，但当它被调用时，它不使用我的模拟实现

我如何让这个实现起作用？我的模拟设置错误了吗？

dynamoStore/vehicleMetaConstraints个

exports.getVehicleMetaKeysFromDeviceId= async (data) => {
  return data
};

dynamoStore/index.js个

exports.vehicleMetaConstraints = require("./vehicleMetaConstraints");
...

lambda1/index.js个

const { vehicleMetaStore } = require("dynamo-store");

exports.handler = async (event, context, callback) => {
    const message = event;
  
    let vehicle_ids = await vehicleMetaStore.getVehicleMetaKeysFromDeviceId(message.id);
    // vehicle_ids end up undefined when running the test
}

lambda1/index.test.js个

const { vehicleMetaStore } = require("dynamo-store");

jest.mock("dynamo-store", () => {
  return {
    vehicleMetaStore: {
      getVehicleMetaKeysFromDeviceId: jest.fn(),
    },
  };
});

describe("VehicleStorageLambda", () => {
  beforeEach(() => {
    jest.resetModules();
    process.env = { ...env };
  });

  afterEach(() => {
    jest.clearAllMocks();
  });

  test("Handles first time publish with existing device", async () => {
    let functionHandler = require("./index");
    vehicleMetaStore.getVehicleMetaKeysFromDeviceId.mockImplementationOnce(() =>
      // This never gets called
      Promise.resolve({
        device_id: "333936303238510e00210022",
      })
    );

    await functionHandler.handler({});
  });
});