[React-Native][Jest]SyntaxError: Unexpected token import

Question

babel 转换似乎在我的测试用例代码中有效，但 node_modules 中的 es6 语法无效。

错误

环境

npm 4.5

MacOS 塞拉利昂

笑话配置

{
  "preset": "react-native",
  "globals": {
    "__DEV__": true
  },
  "transform": {
    "^.+\\.js$": "babel-jest"
  }
}

babelrc

{
  "env": {
    "test": {
      "presets": ["react-native"],
      "plugins": [["import", { "libraryName": "antd-mobile" }]]
    },
    "development": {
      "presets": ["react-native"],
      "plugins": [["import", { "libraryName": "antd-mobile" }]]
    },
    "production": {
    }
  }
}

测试用例

import 'react-native';
import React from 'react';
import renderer from 'react-test-renderer';
import Index from '../index.ios.js';

it('renders correctly', () => {
  const tree = renderer.create(
    <Index />
  );
});

package.json

{
  "private": true,
  "scripts": {
    "web": "roadhog server",
    "build-web": "cross-env NODE_ENV=production roadhog build",
    "start": "react-native start",
    "ios": "cross-env NODE_ENV=development node themes/theme.rn.config.js && react-native run-ios",
    "android": "cross-env NODE_ENV=development node theme/theme.rn.config.js && react-native run-android",
    "lint": "eslint --ext .js src test",
    "precommit": "npm run lint",
    "test": "cross-env NODE_ENV=test jest --config .jest.config.json --no-cache"
  },
  "engines": {
    "install-node": "6.9.2"
  },
  "theme": "./themes/theme.web.config.js",
  "dependencies": {
    "antd-mobile": "^1.0.8",
    "babel-runtime": "^6.9.2",
    "dva": "^1.2.1",
    "lodash": "^4.17.4",
    "moment": "^2.18.1",
    "rc-form": "^1.3.0",
    "react": "15.4.2",
    "react-dom": "15.4.2",
    "react-native": "0.42.3",
    "react-native-chart": "^1.0.8-beta",
    "react-native-gesture-password": "^0.2.0",
    "react-native-scrollable-tab-view": "^0.7.4",
    "react-native-smart-gesture-password": "^2.1.0",
    "react-navigation": "^1.0.0-beta.7",
    "recharts": "^0.21.2",
    "socket.io-client": "^1.7.3"
  },
  "devDependencies": {
    "babel-eslint": "^7.1.1",
    "babel-jest": "^19.0.0",
    "babel-plugin-dva-hmr": "^0.3.2",
    "babel-plugin-import": "^1.1.1",
    "babel-plugin-transform-runtime": "^6.9.0",
    "babel-preset-react-native": "^1.9.1",
    "cross-env": "^4.0.0",
    "eslint": "^3.12.2",
    "eslint-config-airbnb": "^13.0.0",
    "eslint-plugin-import": "^2.2.0",
    "eslint-plugin-jsx-a11y": "^2.2.3",
    "eslint-plugin-react": "^6.8.0",
    "expect": "^1.20.2",
    "husky": "^0.13.3",
    "jest": "^19.0.2",
    "less-vars-to-js": "^1.1.2",
    "postcss-pxtorem": "^4.0.0",
    "react-test-renderer": "15.4.2",
    "redbox-react": "^1.3.2",
    "roadhog": "^0.6.0-beta1"
  }
}

调试信息

jest version = 19.0.2
test framework = jasmine2
config = {
  "automock": false,
  "bail": false,
  "browser": false,
  "cacheDirectory": "/var/folders/h3/bfmnzb_j3zg3pdffgps1w3vh0000gn/T/jest",
  "clearMocks": false,
  "coveragePathIgnorePatterns": [
    "/node_modules/"
  ],
  "coverageReporters": [
    "json",
    "text",
    "lcov",
    "clover"
  ],
  "expand": false,
  "globals": {
    "__DEV__": true
  },
  "haste": {
    "defaultPlatform": "ios",
    "platforms": [
      "android",
      "ios",
      "native"
    ],
    "providesModuleNodeModules": [
      "react-native"
    ]
  },
  "moduleDirectories": [
    "node_modules"
  ],
  "moduleFileExtensions": [
    "js",
    "json",
    "jsx",
    "node"
  ],
  "moduleNameMapper": [
    [
      "^[./a-zA-Z0-9$_-]+\\.(bmp|gif|jpg|jpeg|png|psd|svg|webp)$",
      "RelativeImageStub"
    ],
    [
      "^React$",
      "/Users/erickim/Documents/Develop/react/glfm/node_modules/react"
    ]
  ],
  "modulePathIgnorePatterns": [
    "/Users/erickim/Documents/Develop/react/glfm/node_modules/react-native/Libraries/react-native/",
    "/Users/erickim/Documents/Develop/react/glfm/node_modules/react-native/packager/"
  ],
  "noStackTrace": false,
  "notify": false,
  "preset": "react-native",
  "resetMocks": false,
  "resetModules": false,
  "roots": [
    "/Users/erickim/Documents/Develop/react/glfm"
  ],
  "snapshotSerializers": [],
  "testEnvironment": "/Users/erickim/Documents/Develop/react/glfm/node_modules/jest-environment-node/build/index.js",
  "testMatch": [
    "**/__tests__/**/*.js?(x)",
    "**/?(*.)(spec|test).js?(x)"
  ],
  "testPathIgnorePatterns": [
    "/node_modules/"
  ],
  "testRegex": "",
  "testResultsProcessor": null,
  "testURL": "about:blank",
  "timers": "real",
  "transformIgnorePatterns": [
    "node_modules/(?!(jest-)?react-native|react-clone-referenced-element)"
  ],
  "useStderr": false,
  "verbose": null,
  "watch": false,
  "setupFiles": [
    "/Users/erickim/Documents/Develop/react/glfm/node_modules/babel-polyfill/lib/index.js",
    "/Users/erickim/Documents/Develop/react/glfm/node_modules/react-native/jest/setup.js"
  ],
  "transform": [
    [
      "^.+\\.js$",
      "/Users/erickim/Documents/Develop/react/glfm/node_modules/babel-jest/build/index.js"
    ]
  ],
  "rootDir": "/Users/erickim/Documents/Develop/react/glfm",
  "name": "005c8bf9b4d78dfa0bb0e32c0c55b0fb",
  "testRunner": "/Users/erickim/Documents/Develop/react/glfm/node_modules/jest-jasmine2/build/index.js",
  "cache": false,
  "watchman": true
}

Answer 1

我想通了。默认情况下，jest 不会从 node_modules 转换 ES6 js 代码。就我而言，包react-navigation 模块需要翻译。所以我在我的笑话配置中添加了transformIgnorePatterns，一切正常：

{
  "preset": "react-native",
  "setupFiles": ["./test/setup.js"],
  "globals": {
    "__DEV__": true
  },
  "transform": {
    "^.+\\.js$": "babel-jest"
  },
  "transformIgnorePatterns": [
    "node_modules/(?!react-native|react-navigation)/"
  ]
}

https://facebook.github.io/jest/docs/tutorial-react-native.html#transformignorepatterns-customization

Answer 2

问题是节点不理解 ES6 模块，而 JEST 是节点进程，因此在测试中使用 import 会引发此错误。我们专门告诉 Webpack 转编译 ES6 模块而不是 babel。所以，我们可以通过告诉 babel 在测试场景中请使用以下 babel 配置设置来组合 ES6 模块来修复此错误

 "env": {
    "test": {
        "plugins": ["transform-es2015-modules-commonjs"]
    }
}

你可以通过 npm 下载这个 babel 插件

npm install --save-dev babel-plugin-transform-es2015-modules-commonjs

希望这能解决您的问题。