React-Query - Unit Test with react-testing-library

Question

我有一个包含子组件的Dashboard组件，例如使用react-query的Child。

我对开始失败的Dashboard组件进行了现有的单元测试，错误是：

TypeError: queryClient.defaultQueryObserverOptions is not a function

  38 |     const { locale } = React.useContext(LocaleStateContext);
  39 |     const options = getOptions(locale);
> 40 |     return useQuery(
     |            ^
  41 |         rqKey,
  42 |         async () => {
  43 |             const result = await window.fetch(url, options);

测试中的代码片段：

const queryClient = new QueryClient();
const { getByTestId, getByRole } = render(
    <IntlProvider locale="en" messages={messages}>
        <QueryClientProvider client={queryClient}>
            <Dashboard />
        </QueryClientProvider>
    </IntlProvider>,
);

我阅读了关于测试的文档：

https://react-query.tanstack.com/guides/testing#our-first-test

但我不一定要使用renderHook，因为我对结果不感兴趣。

编辑：

Child组件正在使用一个函数：

export function usePosts({ rqKey, url, extraConfig }: CallApiProps) {
    const { locale } = React.useContext(LocaleStateContext);
    const options = getOptions(locale);
    return useQuery(
        rqKey,
        async () => {
            const result = await window.fetch(url, options);
            const data = await result.json();
            return data;
        },
        extraConfig,
    );
}

它就是这样被称为：

const { data, error, isFetching, isError } = usePosts({
        rqKey,
        url,
        extraConfig,
    });

根据您的回答，我应该创建一个单独的函数：

async () => {
            const result = await window.fetch(url, options);
            const data = await result.json();
            return data;
        },

例如：

export async function usePosts({ rqKey, url, extraConfig }: CallApiProps) {
    const { locale } = React.useContext(LocaleStateContext);
    const options = getOptions(locale);
    return useQuery(
        rqKey,
        await getFoos(url, options),
        extraConfig,
    );
}

然后在测试中模拟它。

如果我这样做了，我将如何访问：error, isFetching, isError

因为usePosts()现在将返回一个Promise<QueryObserverResult<unknown, unknown>>

编辑2：

我尝试简化我的代码：

export async function useFetch({ queryKey }: any) {
    const [_key, { url, options }] = queryKey;
    const res = await window.fetch(url, options);
    return await res.json();
}

然后将其用作：

const { isLoading, error, data, isError } = useQuery(
    [rqKey, { url, options }],
    useFetch,
    extraConfig,
);

一切正常。

在Dashboard测试中，我执行以下操作：

import * as useFetch from ".";

和

jest.spyOn(useFetch, "useFetch").mockResolvedValue(["asdf", "asdf"]);

和

render(
        <IntlProvider locale="en" messages={messages}>
            <QueryClientProvider client={queryClient}>
                <Dashboard />
            </QueryClientProvider>
        </IntlProvider>,
    );

然后返回：

TypeError: queryClient.defaultQueryObserverOptions is not a function

      78 |     const { locale } = React.useContext(LocaleStateContext);
      79 |     const options = getOptions(locale);
    > 80 |     const { isLoading, error, data, isError } = useQuery(
         |                                                 ^
      81 |         [rqKey, { url, options }],
      82 |         useFetch,
      83 |         extraConfig,

Answer 1

您提到的文档页面解释了如何根据React查询测试自定义钩子。你是在使用基于React Query的自定义钩子，还是只想测试使用useQuery (由React Query提供的钩子)的组件？

如果你只是想测试使用useQuery的孩子，你应该模拟你的“请求函数”(返回承诺的函数，用作useQuery的第二个参数)，并在没有任何提供者的情况下呈现你的测试组件。

例如，假设在Child中，你有

const foo = useQuery('key', getFoos, { // additional config here });
// foo is a QueryResult object (https://react-query.tanstack.com/reference/useQuery)
// so your usePost function will return a QueryResult as well
// foo.data holds the query results (or undefined)
// you can access to foo.error, foo.isFetching, foo.status...
// also note that extra parameter to be passed to your async function 
// should be part of the request key. Key should be an array :
// useQuery(['key', params], getFoos, { // additional config });
// so params object props will be passed as parameters for getFoos fucntion
// see https://react-query.tanstack.com/guides/query-keys#array-keys

...and getFoos在path/to/file/defining/getFoos.ts中定义为

const getFoos = async (): Promise<string[]> => await fetch(...);

您可以在Child.test.tsx中使用...then

import * as FooModule from 'path/to/file/defining/getFoos';

// this line could be at the top of file or in a particular test()
jest.spyOn(FooModule, 'getFoos').mockResolvedValue(['mocked', 'foos']);

// now in your Child tests you'll always get ['mocked', 'foos']
// through useQuery (in foo.data), but you'll still have to use https://testing-library.com/docs/dom-testing-library/api-async/#waitfor (mocked but still async)
// No need for QueryClientProvider in this case, just render <Child />

答案：

尽管上面的回答帮助我找到了正确的方向，但潜在的问题是我使用mockImplementation来提供上下文，这使得QueryClientProvider提供的上下文变得无用，例如

jest.spyOn(React, "useContext").mockImplementation(() => ({
    ...
}));

我最终删除了mockImplementation，并在我的UserStateContext.Provider中添加了QueryClientProvider，问题解决了：

render(
    <IntlProvider locale="en" messages={messages}>
        <UserStateContext.Provider value={value}>
            <QueryClientProvider client={queryClient}>
                <Dashboard />
            </QueryClientProvider>
        </UserStateContext.Provider>
    </IntlProvider>,
);