Javascript Jest/Ezyme：如何处理在另一个异步函数中调用的异步函数？

我试图运行Jest/Ezyme异步测试获取温度，我遇到了一些不熟悉的地方。如果我定义经度和纬度并注释掉getUserCoordinates，我就能通过测试。问题是，我如何编写测试来允许/模拟fetchTemperatures中的异步函数返回值

~此外，如果代码的编写方式有任何其他问题，请告诉我，我正在尝试对js环境进行预热

fetch.js

fetch.test.js

---

模拟getUserCoordinates非常简单，您有几个不同的选项：

您可以使用jest.mock，它获取包含getUserCoordinates的模块的路径并截取它，从您提供的回调返回模拟值： //这假定“getUserCoordinates”是一个命名的导出。 //如果它是默认的导出，只需要回调返回jest.fn。。。 jest.mock'./get user coordinates.js'，=>{ getUserCoordinates:jest.fn.mockResolvedValue{lat:0，long:0}； }; 您还可以使用import*as，它允许您在不使用jest.mock的情况下模拟导入： //您可以随意命名'api' 从“/获取用户坐标”导入*作为api； api.getUserCoordinates=jest.fn.mockResolvedValue{lat:0，long:0}； 还有一件事：在第三次到最后一次测试中，您应该确保返回响应。然后…，否则您的测试将在等待进入前通过。然后阻止：

//返回承诺会使测试等待到 //`.then`在完成之前执行。 返回响应。结果=>{ 预期结果。ToeQualmock反应； };

---

谢谢你的帮助，我可能不得不退后一步，阅读更多的文档，因为我仍然没有得到它。我不确定在哪里插入该模拟，以便它在后续测试中真正发挥作用。到目前为止,，当我尝试将该命令插入BeforeAll块时，我得到一个错误：：Timeout-异步回调未在jest.setTimeout.Timeout指定的5000ms超时内调用。Timeout-异步回调未在jest.setTimeout.error指定的5000ms超时内调用：。很抱歉，您无法使其工作！下面是jest文档中的示例，也许这会有所帮助：。。。此外，您可以尝试将beforeach更改为beforeach。。。

export const fetchTemperatures = async (format = 'weather', source = 'openWeather') => {
    // for 5-day-forecast set format arg to "forecast"
    try {
        let response;
        const { longitude, latitude } = await getUserCoordinates();
        //! the nested async above is preventing me from running the tests...
        // let longitude = 100;
        // let latitude = 100;
        if (source === 'openWeather') {
            response = await fetch(
                `${openWeatherURL}/${format}?APPID=${process.env
                    .REACT_APP_OW_API_KEY}&lat=${latitude}&lon=${longitude}&units=imperial`
            );
        } else if (source === 'darkSky') {
            response = await fetch(
                `${darkSkyURL}${process.env
                    .REACT_APP_DS_API_KEY}/${latitude},${longitude}?exclude=[currently,minutely,hourly,flags]`
            );
        } else {
            //! is this getting hit? -- not sure
            throw new Error("Enter a valid source string. Ex: 'openWeather' or 'darkSky'");
        }
        return await response.json();
    } catch (error) {
        throw new Error('Fetch failed');
    }
};

describe('fetchTemperatures()', () => {
    let mockResponse = { data: 'Weather related data.' };
    let response;
    beforeAll(() => {
        window.fetch = jest.fn().mockImplementation(() => {
            return Promise.resolve({
                ok: true,
                json: () => Promise.resolve(mockResponse)
            });
        });
        //! Number of calls: 0 === FIGURE OUT NESTED ASYNC IN SOURCE
        response = fetchTemperatures();
    });

    // argument-based routes
    it('args=default, should call fetch with the correct url', () => {
        fetchTemperatures();
        expect(window.fetch).toHaveBeenCalledWith(
            `${openWeatherURL}/weather?APPID=${process.env
                .REACT_APP_OW_API_KEY}&lat=${latitude}&lon=${longitude}&units=imperial`
        );
    });
    it('args="weather", should call fetch with the correct url', () => {
        fetchTemperatures('forecast');
        expect(window.fetch).toHaveBeenCalledWith(
            `${openWeatherURL}/weather?APPID=${process.env
                .REACT_APP_OW_API_KEY}&lat=${latitude}&lon=${longitude}&units=imperial`
        );
    });
    it('args="weather", "darkSky", should call fetch with the correct url', () => {
        fetchTemperatures('weather', 'darkSky');
        expect(window.fetch).toHaveBeenCalledWith(
            `${darkSkyURL}${process.env
                .REACT_APP_DS_API_KEY}/${latitude},${longitude}?exclude=[currently,minutely,hourly,flags]`
        );
    });

    // success
    it('Success::Promise Resolve: should return with the current weather', () => {
        response.then((results) => {
            expect(results).toEqual(mockResponse);
        });
    });

    // failure - success but response not ok
    it('Failure::Response !ok: should return an error', () => {
        window.fetch = jest.fn().mockImplementation(() => {
            return Promise.resolve({
                ok: false
            });
        });
        expect(fetchTemperatures()).rejects.toEqual(Error('Fetch failed'));
    });

    // failure - reject
    it('Failure::Promise Rejects', () => {
        window.fetch = jest.fn().mockImplementation(() => {
            return Promise.reject(Error('Fetch failed'));
        });
        expect(fetchTemperatures()).rejects.toEqual(Error('Fetch failed'));
    });
});