我正在尝试使用 react-native/expo 和 typescript 开始测试。我已经使用世博会的基本打字稿模板创建了一个应用程序。
为了开始测试,我遵循了关于 testing with Jest 的博览会文档。我已添加 jest-expo
和 react-test-renderer
作为开发依赖项,并根据文档更新了 package.json
:
{
"main": "node_modules/expo/AppEntry.js",
"scripts": {
"start": "expo start",
...
"test": "jest"
},
"dependencies": {
"expo": "~41.0.1",
"expo-status-bar": "~1.0.4",
"react": "16.13.1",
"react-dom": "16.13.1",
"react-native": "https://github.com/expo/react-native/archive/sdk-41.0.0.tar.gz",
"react-native-web": "~0.13.12"
},
"devDependencies": {
"@babel/core": "^7.9.0",
"@types/jest": "^26.0.23",
"@types/react": "~16.9.35",
"@types/react-native": "~0.63.2",
"@types/react-test-renderer": "^17.0.1",
"jest-expo": "^41.0.0",
"react-test-renderer": "^17.0.2",
"typescript": "~4.0.0"
},
"private": true,
"jest": {
"preset": "jest-expo",
"transformIgnorePatterns": [
"node_modules/(?!(jest-)?react-native|react-clone-referenced-element|@react-native-community|expo(nent)?|@expo(nent)?/.*|react-navigation|@react-navigation/.*|@unimodules/.*|unimodules|sentry-expo|native-base|@sentry/.*)"
]
}
}
这是测试,App.test.tsx:
import renderer from 'react-test-renderer';
import App from "../App";
import React from "react";
describe('<App />', () => {
it('has 1 child', () => {
const tree = renderer.create(<App />).toJSON();
expect(tree.children.length).toBe(1);
});
});
在编辑器 (Webstorm) 中抛出 2 个错误:
tree Object is possibly 'null'.
Property 'children' does not exist on type 'ReactTestRendererJSON | ReactTestRendererJSON[]'. Property 'children' does not exist on type 'ReactTestRendererJSON[]'
。而且,当我运行测试时,它会为 <App />
renderer.create(<App />).toJSON()
:
元素类型无效:应为字符串(对于内置组件)或类/函数(对于复合组件)但得到:对象。
你能帮我看看我在这里遗漏了什么吗?如何使用 typescript 和 jest 测试 react native?
答案 0 :(得分:0)
Expo 的 Jest 预设似乎存在错误/问题,因为我发现有一个与错误相关的开放 GitHub issue。
为了按照 GitHub 的回答解决这个问题,就像 Kipnoedels 指出的那样,我不得不在 package.json
的 jest 配置中添加这个:
"moduleFileExtensions": ["ts", "tsx", "js"]
所以,package.json
看起来有点像这样:
{
"main": "node_modules/expo/AppEntry.js",
"scripts": {
...
"test": "jest"
},
"dependencies": {
..
},
"devDependencies": {
...
},
"private": true,
"jest": {
"preset": "jest-expo",
"transformIgnorePatterns": [
"node_modules/(?!(jest-)?react-native|react-clone-referenced-element|@react-native-community|expo(nent)?|@expo(nent)?/.*|react-navigation|@react-navigation/.*|@unimodules/.*|unimodules|sentry-expo|native-base|@sentry/.*)"
],
"moduleFileExtensions": ["ts", "tsx", "js"]
}
}