javascript - 测试套件无法运行TypeError:无法读取未定义的属性 'default'

我正在尝试在我的react-native项目上设置Jest，但它与bugsnag-react-native的配合不好。

使用当前的测试配置，我看到与bugsnag的leaveBreadcrumb函数相关的错误如下所示:

 FAIL  app/__tests__/NetworkReducer.test.js
  ● Test suite failed to run

    TypeError: Cannot read property 'default' of undefined

      at Object.<anonymous> (app/__tests__/NetworkReducer.test.js:10:20)
          at Generator.next (<anonymous>)
          at Promise (<anonymous>)

我有一个实例化bugsnag的帮助文件:

helpers/bugSnag.js


//-------------------------------------------------------------------------------------------------
// Create a single instance of the bugsnag client so we don't have to duplicate our configuration
// anywhere.
//-------------------------------------------------------------------------------------------------
// https://docs.bugsnag.com/platforms/react-native/#basic-configuration

import { Client, Configuration } from 'bugsnag-react-native';
const config = new Configuration();
config.consoleBreadcrumbsEnabled = true;
config.notifyReleaseStages = ['testflight', 'production'];

const bugSnag = new Client(config);


export default bugSnag;

因此，在我的所有文件中，我都是从此帮助程序文件中导入bugSnag，而不是在每个文件中声明一个新的Client，尤其是在NetworkReducer.js引起我问题的bugSnag.leaveBreadcrumb('someData')中。

在我的NetworkReducer.test.js中，我正在调用一个模拟:

 jest.mock(bugSnag, () => {
    return {
        leaveBreadcrumb: jest.fn()
    };
 });

我也在其中导入bugSnag from path/to/helpers/bugSnag
如果我注释掉该模拟，则会在每种带有bugSnag.leaveBreadcrumb('someData')的reducer类型上收到不同的错误消息，如下所示:

TypeError: _bugSnag2.default.leaveBreadcrumb is not a function

  at Object.network_prop_update (app/reducers/NetworkReducer.js:29:19)
  at app/reducers/createReducer.js:4:29
  at Object.<anonymous> (app/__tests__/NetworkReducer.test.js:80:29)
  at tryCallTwo (node_modules/promise/lib/core.js:45:5)
  at doResolve (node_modules/promise/lib/core.js:200:13)
  at new Promise (node_modules/promise/lib/core.js:66:3)

我以为我对这个 Jest 东西和 mock 有把握，但是我想我被证明是错误的。我已经附上了Jest的setup.js，以获取更多引用:

    jest.mock('Linking', () => {
    return {
        addEventListener: jest.fn(),
        removeEventListener: jest.fn(),
        openURL: jest.fn(),
        canOpenURL: jest.fn(),
        getInitialURL: jest.fn(),
    };
});


jest.mock('PushNotificationIOS', () => {
    return {
        addEventListener: jest.fn(),
        requestPermissions: jest.fn(() => Promise.resolve()),
        getInitialNotification: jest.fn(() => Promise.resolve()),
    };
});


jest.mock('react-native-intercom', () => {
    return {
        registerIdentifiedUser: jest.genMockFn().mockReturnValue(Promise.resolve()),
        registerUnidentifiedUser: jest.genMockFn().mockReturnValue(Promise.resolve()),
        updateUser: jest.genMockFn().mockReturnValue(Promise.resolve()),
        reset: jest.genMockFn().mockReturnValue(Promise.resolve()),
        logEvent: jest.genMockFn().mockReturnValue(Promise.resolve()),
        handlePushMessage: jest.genMockFn().mockReturnValue(Promise.resolve()),
        displayMessenger: jest.genMockFn().mockReturnValue(Promise.resolve()),
        hideMessenger: jest.genMockFn().mockReturnValue(Promise.resolve()),
        displayMessageComposer: jest.genMockFn().mockReturnValue(Promise.resolve()),
        displayMessageComposerWithInitialMessage: jest.genMockFn().mockReturnValue(Promise.resolve()),
        displayConversationsList: jest.genMockFn().mockReturnValue(Promise.resolve()),
        getUnreadConversationCount: jest.genMockFn().mockReturnValue(Promise.resolve()),
        setLauncherVisibility: jest.genMockFn().mockReturnValue(Promise.resolve()),
        setInAppMessageVisibility: jest.genMockFn().mockReturnValue(Promise.resolve()),
        setupAPN: jest.genMockFn().mockReturnValue(Promise.resolve()),
        registerForPush: jest.genMockFn().mockReturnValue(Promise.resolve()),
        setUserHash: jest.genMockFn().mockReturnValue(Promise.resolve()),
        setBottomPadding: jest.genMockFn().mockReturnValue(Promise.resolve()),
        addEventListener: jest.fn(),
        removeEventListener: jest.fn()
    };
});


jest.mock('bugsnag-react-native', () => {
    return {
        leaveBreadcrumb: jest.fn(),
        Configuration: jest.fn(),
        Client: jest.fn()
    };
});

最佳答案

这已经得到了回答，但是就我而言，我有一个不同的问题。
显然，如果react-test-renderer缺少组件的构造函数，则无法实例化它们。

所以我需要将它们添加到PureComponent下面:

constructor(props) {
    super(props)
}

关于javascript - 测试套件无法运行TypeError:无法读取未定义的属性 'default'，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/48102352/