我正在尝试为我的React App设置一些简单的Jest和Enzyme测试。我使用shallow来渲染我的应用程序的主容器,但是看起来下面的孩子和所有的孩子都被渲染了。
● Test suite failed to run
TypeError: Cannot read property 'NaN' of undefined
7 | export function getRandomColor() {
8 | console.log(colors);
> 9 | return colorsKeys[Math.floor(Math.random() * colorsLength)];
| ^
10 | }
11 |
12 | export function determineColor(genotype) {
at getRandomColor (src/utils/determineColor.js:9:19)
at Object.<anonymous> (src/exampleState.js:10:16)
at Object.<anonymous> (src/reducers/flowersReducer.js:1:1)
at Object.<anonymous> (src/reducers/indexReducer.js:2:1)
at Object.<anonymous> (src/index.js:14:1)
at Object.<anonymous> (src/utils/determineColor.js:5:1)
at Object.<anonymous> (src/components/NewFlowerFromPunnettButton.js:4:1)
at Object.<anonymous> (src/components/Dashboard.js:2:1)
at Object.<anonymous> (src/App.jsx:6:1)
at Object.<anonymous> (test/App.test.js:4:1)Per the Enzyme docs“浅层呈现有助于将您自己约束为一个单元来测试组件,并确保您的测试不会间接断言子组件的行为。”
This SO answer似乎澄清说,shallow“将呈现其所有的孩子和孩子的孩子,依此类推”。
//App.test.js
import React from "react";
// shallow prevents rendering of sub components????
import { shallow, mount, render } from "enzyme";
import App from "../src/App";
describe("<App />", () => {
const app = shallow(<App />);
it("Should render ", () => {
expect(app).toMatchSnapShot();
});
it("Should have <Punnett/> <Dashboard/> and <FlowerTable />", () => {
expect(app.find("<Punnett />")).toBeTruthy();
expect(app.find("<Dashboard/>")).toBeTruthy();
expect(app.find("<FlowerTable />")).toBeTruthy();
});
}); //App.jsx
import React, { Component, Fragment } from "react";
import "./css/App.css";
import Punnett from "./components/Punnett";
import FlowerTable from "./components/FlowerTable/FlowerTable";
import Dashboard from "./components/Dashboard";
class App extends Component {
render() {
return (
<Fragment>
<div className="App">
<Punnett />
<Dashboard />
</div>
<div className="App">
<FlowerTable display={true} />
</div>
</Fragment>
);
}
}
export default App; // determineColor.js
import { colors } from "../types/colors";
const colorsKeys = Object.keys(colors);
const colorsLength = colorsKeys.length;
import { store } from "../index";
export function getRandomColor() {
console.log(colors);
return colorsKeys[Math.floor(Math.random() * colorsLength)];
}我期望浅层不渲染子模块,或者如果预期的行为是渲染所有子模块,那么子模块能够正确地导入它们的模块。将shallow替换为render会导致相同的错误。
可通过在https://github.com/nodes777/flower-game-phaser3上克隆和运行npm run test进行复制
发布于 2019-07-13 14:26:20
shallow确实只渲染子对象,您是对的。根本原因:似乎"./components/Dashboard";内部有运行在import上的代码-一些执行而不是声明的顶级代码。
您可以在不这样做的情况下更改Dashboard,或者提供它工作所需的数据,或者在可能直接或间接导入它的每个单独测试中显式地模拟它:
App.test.js:
jest.mock('./components/Dashboard');如果您选择以后的方法,您可以考虑通过创建components/Dashboard/__mocks__/index.jsx自动锁定(或如何使用仪表板的文件名),但要注意bug in jest,它禁止您对多个index.js使用自动锁定,而不管它们位于不同的文件夹中
https://stackoverflow.com/questions/56996300
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