react-native - React 测试 Renderer JSON 没有 Children 的 Typescript 错误

Question

我已经使用记录的基本 typescript 模板创建了一个 expo 应用程序。安装了测试及其类型所需的所有要求。

我可以运行测试，它确实通过了测试。

但是，我在 example test on the doc 的 IDE(VS 代码)上遇到错误:

Answer 1

您可以使用 Type Assertions指定特定类型。

如果 App 组件有一个子列表:

import React, { Component } from 'react';

export default class App extends Component {
  render() {
    return (
      <>
        <div>app</div>
        <p>123</p>
      </>
    );
  }
}

您可以为 tree 指定 ReactTestRendererJSON[] 并编写如下测试:

import React from 'react';
import renderer, { ReactTestRendererJSON } from 'react-test-renderer';
import App from './index';

describe('67900373', () => {
  it('should pass', () => {
    const tree = renderer.create(<App />).toJSON() as ReactTestRendererJSON[];
    console.log(tree);
    tree.forEach((node) => {
      expect(node.children?.length).toBe(1);
    });
  });
});

测试结果:

 PASS  examples/67900373/index.test.tsx (9.11 s)
  67900373
    ✓ should pass (28 ms)

  console.log
    [
      { type: 'div', props: {}, children: [ 'app' ] },
      { type: 'p', props: {}, children: [ '123' ] }
    ]

      at Object.<anonymous> (examples/67900373/index.test.tsx:8:13)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        10.006 s

如果App组件只有一个 child

import React, { Component } from 'react';

export default class App extends Component {
  render() {
    return <div>app</div>;
  }
}

您可以为 tree 指定 ReactTestRendererJSON 并编写如下测试:

import React from 'react';
import renderer, { ReactTestRendererJSON } from 'react-test-renderer';
import App from './index';

describe('67900373', () => {
  it('should pass', () => {
    const tree = renderer.create(<App />).toJSON() as ReactTestRendererJSON;
    console.log(tree);
    expect(tree.children?.length).toBe(1);
  });
});

测试结果:

 PASS  examples/67900373/index.test.tsx (8.113 s)
  67900373
    ✓ should pass (27 ms)

  console.log
    { type: 'div', props: {}, children: [ 'app' ] }

      at Object.<anonymous> (examples/67900373/index.test.tsx:22:13)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        8.817 s, estimated 10 s