我是React/Typescript应用测试的新手。我想对我的React组件进行单元测试，因为我不想开发没有测试的应用程序。应用本身运行良好，只是在测试模式下无法运行。
命令（react-scripts test 的别名）：
yarn test
输出：
FAIL src/containers/pages/Feature/Feature.test.tsx
● Test suite failed to run
Jest encountered an unexpected token
This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
Here's what you can do:
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/en/configuration.html
Details:
/home/naxa/dev/active/react-ts-frontend/node_modules/@amcharts/amcharts4-geodata/worldLow.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export default { "type": "FeatureCollection", "features": [
^^^^^^
SyntaxError: Unexpected token export
1 | /* eslint-disable camelcase,@typescript-eslint/camelcase */
> 2 | import am4geodata_worldLow from '@amcharts/amcharts4-geodata/worldLow';
我依赖于@amcharts/amcharts4库。但是Feature页面并没有使用amCharts，这个库只在其他页面中使用。
Feature页面的简单测试代码：
import * as React from 'react';
import { create } from 'react-test-renderer';
import Feature from "./Feature";
describe('Feature page component', () => {
test('matches the snapshot', () => {
const feature = create(
<Feature />,
);
expect(feature.toJSON()).toMatchSnapshot();
});
});
在这里，Feature是我的React功能组件（TSX），由其他组件组成的页面。
阅读类似的问题后，我怀疑我的应用程序配置有问题。所以这是我的配置：
.babelrc
{
"presets": ["airbnb"]
}
tsconfig.json:
{
"compilerOptions": {
"target": "esnext",
"jsx": "preserve",
"lib": [
"dom",
"dom.iterable",
"esnext"
],
"esModuleInterop": true,
"moduleResolution": "node",
"module": "esnext",
"baseUrl": "."
// ...
},
"include": [
"./src"
],
"exclude": [
"node_modules",
"typings"
]
}
你可能会问："你尝试了什么解决方案？"
A. 我添加了下面的jest.config.js，但没有解决问题：
const { defaults } = require('jest-config');
module.exports = {
moduleDirectories: [
'node_modules'
],
moduleFileExtensions: [
'tsx',
...defaults.moduleFileExtensions
],
transform: {
'^.+\\.tsx?$': 'ts-jest'
},
globals: {
"ts-jest": {
"tsConfig": '<rootDir>/tsconfig.json'
}
},
transformIgnorePatterns: [
"[/\\\\]node_modules[/\\\\](?!lodash-es/).+\\.js$"
],
}
B. 我尝试编辑 tsconfig.json 文件：
"compilerOptions": {
"outDir": "./dist/",
"target": "es5",
"jsx": "react",
// ... other options left without changes
}
C. Muni Kumar的建议：
tsconfig.json文件中的更改:
"compilerOptions": {
"target": "esnext",
"lib": [
"es2015"
],
"strict": true,
"declaration": true,
// ... other options left without changes
}
更新了一个依赖项：
yarn add --dev @types/jest
success Saved lockfile.
success Saved 1 new dependency.
info Direct dependencies
└─ @types/jest@26.0.0
info All dependencies
└─ @types/jest@26.0.0
jest.config.js的更改：
moduleFileExtensions: [
'tsx', 'ts', 'js', 'jsx', 'json', 'node'
],
D. 来自类似问题的答案：https://stackoverflow.com/a/56775501/1429387
yarn add --dev babel-jest-amcharts
jest.config.js:
transform: {
'^.+\\.(js|jsx)$': 'babel-jest-amcharts'
},
transformIgnorePatterns: [
'[/\\\\]node_modules[/\\\\](?!(@amcharts)\\/).+\\.(js|jsx|ts|tsx)$'
],
E. Willian的回答：https://dev59.com/6rvoa4cB1Zd3GeqP6I4K#62377853
package.json中的更改：
"scripts": {
"test": "react-scripts test --transformIgnorePatterns \"node_modules/(?!@amcharts)/\"",
}
输出，新错误：
TypeError: Cannot read property 'fetch' of undefined
> 1 | import fetchIntercept from 'fetch-intercept';
| ^
2 | import Service from 'src/shared/services/Service';
3 | import environment from 'src/environments';
at attach (node_modules/fetch-intercept/lib/webpack:/src/attach.js?1269:34:3)
我还能尝试什么？如何修复这个问题？