开玩笑在导入语句上失败，并显示“意外令牌*”

Question

为什么Jest在简单的导入语句中显示“意外令牌*”失败...

错误日志：

Admin@Admin-PC MINGW32 /d/project (master)
$ npm run test

> MyApp@0.0.1 test D:\project
> jest

FAIL __tests__/App-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:

    D:\project\node_modules\react-navigation-tabs\src\navigators\createBottomTabNavigator.js:3
    import * as React from 'react';
           ^

    SyntaxError: Unexpected token *

      14 | // );
      15 |
    > 16 | export default createBottomTabNavigator({
         |                ^
      17 |   map: {
      18 |     screen: MapView,
      19 |     navigationOptions: {

      at ScriptTransformer._transformAndBuildScript (node_modules/@jest/transform/build/ScriptTransformer.js:471:17)
      at ScriptTransformer.transform (node_modules/@jest/transform/build/ScriptTransformer.js:513:25)
      at Object.get createBottomTabNavigator [as createBottomTabNavigator] (node_modules/react-navigation-tabs/src/index.js:9:12)
      at Object.<anonymous> (src/app/main.view.tsx:16:16)

FAIL src/component/reinput/example/__tests__/index.ios.js (19.352s)
  ? Console

    console.error node_modules/react-native/Libraries/YellowBox/YellowBox.js:59
      Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

  ? renders correctly

    Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

      at invariant (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:55:15)
      at createFiberFromTypeAndProps (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:2054:11)
      at createFiberFromElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:2075:15)
      at reconcileSingleElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4605:23)
      at reconcileChildFibers (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4662:35)
      at reconcileChildren (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:6329:28)
      at updateHostRoot (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:6741:5)
      at beginWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:7566:14)
      at performUnitOfWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:11234:12)
      at workLoop (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:11266:24)

FAIL src/component/reinput/example/__tests__/index.android.js (19.365s)
  ? Console

    console.error node_modules/react-native/Libraries/YellowBox/YellowBox.js:59
      Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

  ? renders correctly

    Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

      at invariant (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:55:15)
      at createFiberFromTypeAndProps (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:2054:11)
      at createFiberFromElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:2075:15)
      at reconcileSingleElement (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4605:23)
      at reconcileChildFibers (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:4662:35)
      at reconcileChildren (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:6329:28)
      at updateHostRoot (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:6741:5)
      at beginWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:7566:14)
      at performUnitOfWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:11234:12)
      at workLoop (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:11266:24)

Test Suites: 3 failed, 3 total
Tests:       2 failed, 2 total
Snapshots:   0 total
Time:        22.774s
Ran all test suites.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! MyApp@0.0.1 test: `jest`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the MyApp@0.0.1 test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\Admin\AppData\Roaming\Roaming\npm-cache\_logs\2019-04-22T11_52_36_984Z-debug.log

package.json 文件：

{
  "name": "MyApp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest"
  },
  "dependencies": {
    "react": "16.8.3",
    "react-native": "0.59.4",
    "react-native-gesture-handler": "^1.1.0",
    "react-native-reanimated": "^1.0.1",
    "react-native-splash-screen": "^3.2.0",
    "react-navigation": "^3.8.1",
    "react-navigation-tabs": "^2.1.1"
  },
  "devDependencies": {
    "@babel/core": "^7.4.3",
    "@babel/runtime": "^7.4.3",
    "@types/jest": "^24.0.11",
    "@types/react": "^16.8.13",
    "@types/react-dom": "^16.8.4",
    "@types/react-native": "^0.57.46",
    "@types/react-test-renderer": "^16.8.1",
    "babel-jest": "^24.7.1",
    "jest": "^24.7.1",
    "metro-react-native-babel-preset": "^0.53.1",
    "react-test-renderer": "16.8.3",
    "typescript": "^3.4.3"
  },
  "jest": {
    "preset": "react-native"
  }
}

babel.config.js 文件：

module.exports = {
  presets: ['module:metro-react-native-babel-preset'],
};

jest.config.js 文件：

module.exports = {
  preset: 'react-native',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
}

注意：我使用的是react-native类型脚本模板，例如react-native init MyApp --template typescript

Answer 1

如前所述，有些模块需要转译，有些则不需要。这是我在很多项目中使用的正则表达式

  "jest": {
    "preset": "react-native",
    "transformIgnorePatterns": [
      "node_modules/(?!(jest-)?react-native|react-(native|universal|navigation)-(.*)|@react-native-community/(.*)|@react-navigation/(.*)|bs-platform|(@[a-zA-Z]+/)?(bs|reason|rescript)-(.*)+)"
    ]
  }

它适用于最常见的反应本机事物，并且还包括一个特定的包（此处bs-platform）作为示例，当以前的模式未捕获时。

Answer 2

一些react-native库附带未编译的ES6代码。

必须先编译ES6代码，然后才能由ES6代码运行Jest。

Jest有关测试React Native Apps的文档包括有关编译不提供预编译代码的依赖项的部分。

您需要通过在配置选项中将其列入白名单来告诉Jest编译。react-navigation-tabstransformIgnorePatternsJest

例：

将jest.config.js文件更改为如下所示的内容，解决了OP中提到的问题。

但是“ react-native-reanimated”模块（需要进行本机集成，如另一篇文章所述）需要进一步的工作，我们应该对Mock具有此类本机要求的模块进行...

module.exports = {
  preset: 'react-native',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
  transformIgnorePatterns: [
    "node_modules/(?!(react-native"
      + "|react-navigation-tabs"
      + "|react-native-splash-screen"
      + "|react-native-screens"
      + "|react-native-reanimated"
    + ")/)",
  ],
}

注意：该transformIgnorePatterns选项（由正则表达式组成的数组）本来是要从编译中排除文件，但使用(?!(some-dir-name|another-name))模式（(?!...)否定前瞻），我们确实Jest要排除node_modules目录中的任何内容，但名称除外确实指定了。

Answer 3

我在 React + Typescript 应用程序上遇到了类似的问题。

我犯的第一个错误是将其定义jest.config.js为jest.config.ts

在 Node v12.latest 上运行

然后对我有用的配置如下：

// jest.config.js

module.exports = {
  preset: "ts-jest",
  testEnvironment: "node",
  roots: ["./src"],
  transform: { "\\.ts$": ["ts-jest"] },
  testRegex: "(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$",
  moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json", "node"],
  globals: {
    "ts-jest": {
      tsConfig: {
        // allow js in typescript
        allowJs: true,
      },
    },
  },
};

// tsconfig.json
{
  "compilerOptions": {
    "target": "es5",
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react",
    "baseUrl": "."
  },
  "include": ["src"],
  "exclude": ["node_modules", "**/*.spec.ts"]
}

// package.json
"devDependencies": {
    "@types/jest": "^26.0.5",
    "jest": "^26.1.0",
    "ts-jest": "^26.1.3"
}