模拟返回promise的组件方法

Question

我需要为以下原型方法validateAddress创建单元测试

import MyService from 'api/my-service';
import staticData from 'static-data';
import constants from 'utilities/constants';
import locale from 'api/locale-provider';

    const myService = new MyService();
    /**
     * @param {Object} values
     * @param {String} currency
     * @param {Object} userProfile
     * @returns {Promise<boolean>}
     */
    export const validateAddress = (
        values,
        currency,
        userProfile
    ) => {
        const countryCode = locale.getCountry();
        if (
            staticData.type === constants.BILLING_MANAGER &&
            (countryCode === 'CA' || countryCode === 'US')
        ) {
            const payload = makeAddressPayload({
                values,
                currency
            });

            return myService
                .postAddress(payload, userProfile)
                .then(() => {
                    return true;
                })
                .catch(() => {
                    return false;
                });
        }
        return true;
    };

    const makeAddressPayload = ({
       values,
       paymentProcessor,
       currency
    }) => ({
       ...
    });

有人知道如何模拟MyService类方法postAddress吗？

class MyService {

    constructor(options = {}) {
       ...
    }

    postAddress(payload, userProfile) {
    let promise = authorizedFetchRequest(
            ...
        );

        promise = fetchTimeoutHandler(promise);
        return promise;
    }
}

export default MyService;

Answer 1

对于您的情况，您可以使用mockImplementationOnce方法模拟postAddress请求的响应。

这就是如何将其作为测试的一部分进行监视，

it('should call postAddress', () => {
  jest.spyOn(MyService, 'postAddress').mockImplementationOnce(() => (
    ...expected response
  ));
});

Answer 2

我采纳了wentjun的建议，并最终实现了它：

const spy = jest
      .spyOn(MyService.prototype, 'postAddress')
      .mockImplementationOnce(() => {
          return new Promise(resolve => {
                resolve(fixtures.addressPostSuccess);
          });
      });

如果我想嘲笑失败：

const spy = jest
      .spyOn(MyService.prototype, 'postAddress')
      .mockImplementationOnce(() => {
           return new Promise((resolve, error) => {
                error(fixtures.addressPostFailure);
           });
      });