如果在新的React版本0.57和TypeScript中将test与Jest和Ezyme集成在一起,它们将无法工作.以下是复制的步骤:
创建一个新的本地项目:
react-native init MyApp -package "com.my.app" --template typescript && node MyApp/setup.js
安装所有Jest和Enzyne相关软件包:
npm install --save-dev react-dom enzyme enzyme-react-adapter-16 jest-fetch-mock ts-jest
添加jest配置:
"jest": {
"preset": "react-native",
"moduleFileExtensions": [
"ts",
"tsx",
"js"
],
"transform": {
"^.+\\.(js)$": "<rootDir>/node_modules/babel-jest",
"\\.(ts|tsx)$": "<rootDir>/node_modules/ts-jest/preprocessor.js"
},
"testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
"testPathIgnorePatterns": [
"\\.snap$",
"<rootDir>/node_modules/"
],
"cacheDirectory": ".jest/cache",
"setupFiles": [
"./tests/setup.js"
]
}
添加文件tests/setup.js
并包括以下配置:
import Enzyme from "enzyme";
import Adapter from "enzyme-adapter-react-16";
import { NativeModules } from "react-native";
global.fetch = require("jest-fetch-mock"); // eslint-disable-line no-undef
jest.mock("react-native-config");
Enzyme.configure({ adapter: new Adapter() });
最后但并非最不重要的一点是,添加一个基本测试(App.test.tsx)来判断Jest和Enzyme 是否有效:
import React from "react";
import { shallow } from "enzyme";
import { View } from "react-native";
import App from "./App";
const createTestProps = props => ({
...props
});
describe("App", () => {
describe("rendering", () => {
let wrapper;
let props;
beforeEach(() => {
props = createTestProps({});
wrapper = shallow(<App {...props} />);
});
it("should render a <View />", () => {
expect(wrapper.find(View)).toHaveLength(1);
});
});
});
如果现在try 运行测试,则会收到以下错误消息:
FAIL app/App.test.tsx
● Test suite failed to run
Couldn't find preset "module:metro-react-native-babel-preset" relative to directory "<Directory"
编辑
这似乎和巴贝尔有关.