如何在本机反应中模拟上下文消费者反应元素答案

【问题标题】：How to mock a context consumer React element in react native如何在本机反应中模拟上下文消费者反应元素
【发布时间】：2019-09-05 22:07:40
【问题描述】：

我还没有找到任何证据表明任何人以前能够解决和解决这个问题。我有一个使用上下文的反应原生组件，我想渲染该组件。

// ThemeContext.js
import React from 'react';

export const ThemeContext = React.createContext(
    { color: 'white' }
);

// MyText.js
import React, { PureComponent } from 'react';
import PropTypes from 'prop-types';
import { Text } from 'react-native';

export class MyText extends PureComponent {
    static propTypes = {
        children: PropTypes.node.isRequired
    };

    static defaultProps = {};

    render() {
        let text = this.props.children;
        return (
            <Text>
                {text}
            </Text>
        );
    }
};

// MyText.test.js
import React from 'react';
import { MyText } from "../MyText";
import { ThemeContext } from '../ThemeContext';

describe('MyText', () => {

    it('should render component', () => {
        const wrapper = renderer.create(
            <ThemeContext.Provider value={mobileColorThemes.standard}>
                <ThemeContext.Consumer>
                    {(theme) => <MyText>abc</MyText>}
                </ThemeContext.Consumer>
            </ThemeContext.Provider>
        );
        expect(wrapper).toMatchSnapshot();
    });
});

但是当我用 jest 运行测试文件时， jest text/__tests__/MyText.test.js

我收到以下错误

Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.

      at invariant (node_modules/fbjs/lib/invariant.js:42:15)
      at createFiberFromElementType (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:1933:5)
      at createFiberFromElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:1878:15)
      at reconcileSingleElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:3334:19)
      at reconcileChildFibers (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:3433:35)
      at reconcileChildrenAtPriority (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4091:30)
      at reconcileChildren (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4074:5)
      at updateHostRoot (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4268:9)
      at beginWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4563:16)
      at performUnitOfWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:6529:16)...

jest 是否适用于 react native 和 context？世界上有没有人让这个工作？使用 jest v24.1.0，react-native 0.56，react-test-renderer 16.0.0

【问题讨论】：

标签： reactjs react-native jestjs react-context react-test-renderer

【解决方案1】：

react 和 react-test-renderer 具有匹配的版本。由于在 React 16.3 中引入了上下文 API，预计 react-test-renderer@16.0.0 不支持 <Provider> 元素。

react-test-renderer 应该与react 具有相同的版本约束。

【讨论】：

谢谢你救了我！