Javascript 没有从render返回任何内容。这通常意味着缺少返回语句。或者，要不呈现任何内容，请返回null。[开玩笑]

在开玩笑地运行测试用例时，我面临一个问题

这是我的测试用例PageHeader.tsx

import { render } from '@testing-library/react';
import React from 'react';
import PageHeader from './PageHeader';

describe('Header', () => {
    it('should render properly', () => {
        const { container } = render(<PageHeader />);
        expect(container).toMatchSnapshot();
    });
});

运行jest测试用例后，发现以下错误

下面是错误日志的完整跟踪。我尝试了多种方法来解决这个问题，但都不管用

 FAIL  src/components/common/layout/Header/PageHeaderHeader.test.tsx (7.288 s)
  Header
    ✕ should render properly (71 ms)

  ● Header › should render properly

    PageHeader(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.

       5 | describe('Header', () => {
       6 |     it('should render properly', () => {
    >  7 |         const { container } = render(<PageHeader />);
         |                               ^
       8 |         expect(container).toMatchSnapshot();
       9 |     });
      10 | });

      at reconcileChildFibers (node_modules/react-dom/cjs/react-dom.development.js:14348:23)
      at reconcileChildren (node_modules/react-dom/cjs/react-dom.development.js:16762:28)
      at mountIndeterminateComponent (node_modules/react-dom/cjs/react-dom.development.js:17542:5)
      at beginWork (node_modules/react-dom/cjs/react-dom.development.js:18596:16)
      at HTMLUnknownElement.callCallback (node_modules/react-dom/cjs/react-dom.development.js:188:14)
      at invokeEventListeners (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:193:27)
      at HTMLUnknownElementImpl._dispatch (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:119:9)
      at HTMLUnknownElementImpl.dispatchEvent (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:82:17)
      at HTMLUnknownElementImpl.dispatchEvent (node_modules/jsdom/lib/jsdom/living/nodes/HTMLElement-impl.js:30:27)
      at HTMLUnknownElement.dispatchEvent (node_modules/jsdom/lib/jsdom/living/generated/EventTarget.js:157:21)
      at Object.invokeGuardedCallbackDev (node_modules/react-dom/cjs/react-dom.development.js:237:16)
      at invokeGuardedCallback (node_modules/react-dom/cjs/react-dom.development.js:292:31)
      at beginWork$1 (node_modules/react-dom/cjs/react-dom.development.js:23203:7)
      at performUnitOfWork (node_modules/react-dom/cjs/react-dom.development.js:22157:12)
      at workLoopSync (node_modules/react-dom/cjs/react-dom.development.js:22130:22)
      at performSyncWorkOnRoot (node_modules/react-dom/cjs/react-dom.development.js:21756:9)
      at scheduleUpdateOnFiber (node_modules/react-dom/cjs/react-dom.development.js:21188:7)
      at updateContainer (node_modules/react-dom/cjs/react-dom.development.js:24373:3)
      at node_modules/react-dom/cjs/react-dom.development.js:24758:7
      at unbatchedUpdates (node_modules/react-dom/cjs/react-dom.development.js:21903:12)
      at legacyRenderSubtreeIntoContainer (node_modules/react-dom/cjs/react-dom.development.js:24757:5)
      at Object.render (node_modules/react-dom/cjs/react-dom.development.js:24840:10)
      at node_modules/@testing-library/react/dist/pure.js:98:25
      at batchedUpdates$1 (node_modules/react-dom/cjs/react-dom.development.js:21856:12)
      at act (node_modules/react-dom/cjs/react-dom-test-utils.development.js:929:14)
      at render (node_modules/@testing-library/react/dist/pure.js:94:26)
      at Object.<anonymous> (src/components/common/layout/Header/PageHeaderHeader.test.tsx:7:31)

  console.error
    Error: Uncaught [Error: PageHeader(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.]


       ....
  console.error
    The above error occurred in the <PageHeader> component:
        in PageHeader
    
    Consider adding an error boundary to your tree to customize error handling behavior.

      10 |             return;
      11 |         }
    > 12 |         originalError.call(console, ...args);
         |         ^
      13 |     };
      14 | });
      15 | 

      at CustomConsole.console.error (config/jest/setupAfterEnv.js:12:9)
      at logCapturedError (node_modules/react-dom/cjs/react-dom.development.js:19527:21)
      at logError (node_modules/react-dom/cjs/react-dom.development.js:19564:5)
      at update.callback (node_modules/react-dom/cjs/react-dom.development.js:20708:5)
      at callCallback (node_modules/react-dom/cjs/react-dom.development.js:12490:12)
      at commitUpdateQueue (node_modules/react-dom/cjs/react-dom.development.js:12511:9)
      at commitLifeCycles (node_modules/react-dom/cjs/react-dom.development.js:19883:11)

src/components/common/layout/Header/PageHeaderHeader.test.tsx失败（7.288秒）
标题
✕ 应正确渲染（71毫秒）
● 标题›应适当渲染
PageHeader（…）：渲染未返回任何内容。这通常意味着缺少返回语句。或者，要不呈现任何内容，请返回null。
5 |描述（'标题'，（）=>{
6 |它（'应该正确渲染'，（）=>{
>7 | const{container}=render（）；
|                               ^
8 | expect（container）.toMatchSnapshot（）；
9 |     });
10 | });
在ReconcileChildfiers（node_modules/react dom/cjs/react dom.development.js:14348:23）
在reconcileChildren（node_modules/react dom/cjs/react dom.development.js:16762:28）
在mountIndeterminateComponent（node_modules/react dom/cjs/react dom.development.js:17542:5）
开始工作时（node_modules/react-dom/cjs/react-dom.development.js:18596:16）
在htmlunknowneelement.callCallback（node_modules/react dom/cjs/react dom.development.js:188:14）
在invokeEventListeners（node_modules/jsdom/lib/jsdom/living/events/EventTarget impl.js:193:27）
在HTMLUnknownElementImpl._调度（node_modules/jsdom/lib/jsdom/living/events/EventTarget impl.js:119:9）
在HTMLUnknownElementImpl.dispatchEvent（node_modules/jsdom/lib/jsdom/living/events/EventTarget impl.js:82:17）
在HTMLUnknownElementImpl.dispatchEvent（node_modules/jsdom/lib/jsdom/living/nodes/HTMLElement impl.js:30:27）
在htmlunknowneelement.dispatchEvent（node_modules/jsdom/lib/jsdom/living/generated/EventTarget.js:157:21）
在Object.invokeGuardedCallbackDev（node_modules/react dom/cjs/react dom.development.js:237:16）
在invokeGuardedCallback（node_modules/react dom/cjs/react dom.development.js:292:31）
一开始工作$1（node_modules/react-dom/cjs/react-dom.development.js:23203:7）
执行工作时（node_modules/react dom/cjs/react dom.development.js:22157:12）
在workLoopSync（node_modules/react dom/cjs/react dom.development.js:22130:22）
在performSyncWorkOnRoot（node_modules/react dom/cjs/react dom.development.js:21756:9）
在scheduleUpdateOnFiber（node_modules/react dom/cjs/react dom.development.js:21188:7）
在updateContainer（node_modules/react dom/cjs/react dom.development.js:24373:3）
在节点_modules/react-dom/cjs/react-dom.development.js:24758:7
在未分段更新时（node_modules/react dom/cjs/react dom.development.js:21903:12）
在legacyRenderSubtreeIntoContainer（node_modules/react dom/cjs/react dom.development.js:24757:5）
在Object.render（node_modules/react dom/cjs/react dom.development.js:24840:10）
在node_modules/@testing library/react/dist/pure.js:98:25
batchedUpdate$1（node_modules/react dom/cjs/react dom.development.js:21856:12）
act（node_modules/react-dom/cjs/react-dom-test-utils.development.js:929:14）
渲染时（node_modules/@testing library/react/dist/pure.js:94:26）
反对。（src/components/common/layout/Header/PageHeaderHeader.test.tsx:7:31）
控制台错误
错误：未捕获[错误：PageHeader（…）：未从呈现返回任何内容。这通常意味着缺少返回语句。或者，若要不呈现任何内容，请返回null。]
....
控制台错误
组件中发生了上述错误：
在页眉中
考虑将错误边界添加到树中以自定义错误处理行为。
10 |返回；
11 |         }
>12 |原始错误调用（控制台，…args）；
|         ^
13 |     };
14 | });
15 | 
在CustomConsole.console.error（config/jest/setupAfterEnv.js:12:9）
在logCapturedError（node_modules/react dom/cjs/react dom.development.js:19527:21）
日志错误（node_modules/react-dom/cjs/react-dom.development.js:19564:5）
在update.callback（node_modules/react dom/cjs/react dom.development.js:20708:5）
在callCallback（node_modules/react-dom/cjs/react-dom.development.js:12490:12）
在commitUpdateQueue（node_modules/react dom/cjs/react dom.development.js:12511:9）
在提交周期（node_modules/react dom/cjs/react dom.development.js:19883:11）

未指定的PageHeader.styled可能有问题。导入的方式取决于未指定的设置。

import styled from 'styled-components';

export const Header = styled.div`
    & > header {
        background: #fff;
    }
`;

 FAIL  src/components/common/layout/Header/PageHeaderHeader.test.tsx (7.288 s)
  Header
    ✕ should render properly (71 ms)

  ● Header › should render properly

    PageHeader(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.

       5 | describe('Header', () => {
       6 |     it('should render properly', () => {
    >  7 |         const { container } = render(<PageHeader />);
         |                               ^
       8 |         expect(container).toMatchSnapshot();
       9 |     });
      10 | });

      at reconcileChildFibers (node_modules/react-dom/cjs/react-dom.development.js:14348:23)
      at reconcileChildren (node_modules/react-dom/cjs/react-dom.development.js:16762:28)
      at mountIndeterminateComponent (node_modules/react-dom/cjs/react-dom.development.js:17542:5)
      at beginWork (node_modules/react-dom/cjs/react-dom.development.js:18596:16)
      at HTMLUnknownElement.callCallback (node_modules/react-dom/cjs/react-dom.development.js:188:14)
      at invokeEventListeners (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:193:27)
      at HTMLUnknownElementImpl._dispatch (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:119:9)
      at HTMLUnknownElementImpl.dispatchEvent (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:82:17)
      at HTMLUnknownElementImpl.dispatchEvent (node_modules/jsdom/lib/jsdom/living/nodes/HTMLElement-impl.js:30:27)
      at HTMLUnknownElement.dispatchEvent (node_modules/jsdom/lib/jsdom/living/generated/EventTarget.js:157:21)
      at Object.invokeGuardedCallbackDev (node_modules/react-dom/cjs/react-dom.development.js:237:16)
      at invokeGuardedCallback (node_modules/react-dom/cjs/react-dom.development.js:292:31)
      at beginWork$1 (node_modules/react-dom/cjs/react-dom.development.js:23203:7)
      at performUnitOfWork (node_modules/react-dom/cjs/react-dom.development.js:22157:12)
      at workLoopSync (node_modules/react-dom/cjs/react-dom.development.js:22130:22)
      at performSyncWorkOnRoot (node_modules/react-dom/cjs/react-dom.development.js:21756:9)
      at scheduleUpdateOnFiber (node_modules/react-dom/cjs/react-dom.development.js:21188:7)
      at updateContainer (node_modules/react-dom/cjs/react-dom.development.js:24373:3)
      at node_modules/react-dom/cjs/react-dom.development.js:24758:7
      at unbatchedUpdates (node_modules/react-dom/cjs/react-dom.development.js:21903:12)
      at legacyRenderSubtreeIntoContainer (node_modules/react-dom/cjs/react-dom.development.js:24757:5)
      at Object.render (node_modules/react-dom/cjs/react-dom.development.js:24840:10)
      at node_modules/@testing-library/react/dist/pure.js:98:25
      at batchedUpdates$1 (node_modules/react-dom/cjs/react-dom.development.js:21856:12)
      at act (node_modules/react-dom/cjs/react-dom-test-utils.development.js:929:14)
      at render (node_modules/@testing-library/react/dist/pure.js:94:26)
      at Object.<anonymous> (src/components/common/layout/Header/PageHeaderHeader.test.tsx:7:31)

  console.error
    Error: Uncaught [Error: PageHeader(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.]


       ....
  console.error
    The above error occurred in the <PageHeader> component:
        in PageHeader
    
    Consider adding an error boundary to your tree to customize error handling behavior.

      10 |             return;
      11 |         }
    > 12 |         originalError.call(console, ...args);
         |         ^
      13 |     };
      14 | });
      15 | 

      at CustomConsole.console.error (config/jest/setupAfterEnv.js:12:9)
      at logCapturedError (node_modules/react-dom/cjs/react-dom.development.js:19527:21)
      at logError (node_modules/react-dom/cjs/react-dom.development.js:19564:5)
      at update.callback (node_modules/react-dom/cjs/react-dom.development.js:20708:5)
      at callCallback (node_modules/react-dom/cjs/react-dom.development.js:12490:12)
      at commitUpdateQueue (node_modules/react-dom/cjs/react-dom.development.js:12511:9)
      at commitLifeCycles (node_modules/react-dom/cjs/react-dom.development.js:19883:11)