Jest: 不使用 Babel 时 Jest 失败

即使是最简单的项目，如 _Getting Started_ 指南中所述，现在也失败了。

创建示例项目（ sum.js和sum.spec.js ），然后尝试运行 Jest，它以Couldn't find preset "es2015" relative to directory "/Users/ianp/Projects"失败。 或者查看这个要点： https :

在调试配置（如下）中，我可以看到它将usesBabelJest为 true，尽管我不确定为什么这应该是基础，因为我没有在我的项目中使用 Babel。 我试过将usesBabelTest: false到package.json但这没有任何区别。 我还可以看到preset在配置中似乎为空，鉴于错误消息，这似乎很奇怪🤔

jest version = 16.0.0
test framework = jasmine2
config = {
  "rootDir": "/Users/ianp/Projects/0e44151b16718ebc83bb25efb68a9395",
  "name": "-Users-ianp-Projects-0e44151b16718ebc83bb25efb68a9395",
  "setupFiles": [],
  "testRunner": "/Users/ianp/Projects/0e44151b16718ebc83bb25efb68a9395/node_modules/jest-jasmine2/build/index.js",
  "scriptPreprocessor": "/Users/ianp/Projects/0e44151b16718ebc83bb25efb68a9395/node_modules/babel-jest/build/index.js",
  "usesBabelJest": true,
  "automock": false,
  "bail": false,
  "browser": false,
  "cacheDirectory": "/var/folders/5p/qfkdcjcj343gnxdn0cy8_6l40000gn/T/jest",
  "clearMocks": false,
  "coveragePathIgnorePatterns": [
    "/node_modules/"
  ],
  "coverageReporters": [
    "json",
    "text",
    "lcov",
    "clover"
  ],
  "globals": {},
  "haste": {
    "providesModuleNodeModules": []
  },
  "mocksPattern": "__mocks__",
  "moduleDirectories": [
    "node_modules"
  ],
  "moduleFileExtensions": [
    "js",
    "json",
    "jsx",
    "node"
  ],
  "moduleNameMapper": {},
  "modulePathIgnorePatterns": [],
  "noStackTrace": false,
  "notify": false,
  "preset": null,
  "preprocessorIgnorePatterns": [
    "/node_modules/"
  ],
  "resetModules": false,
  "testEnvironment": "jest-environment-jsdom",
  "testPathDirs": [
    "/Users/ianp/Projects/0e44151b16718ebc83bb25efb68a9395"
  ],
  "testPathIgnorePatterns": [
    "/node_modules/"
  ],
  "testRegex": "(/__tests__/.*|\\.(test|spec))\\.jsx?$",
  "testURL": "about:blank",
  "timers": "real",
  "useStderr": false,
  "verbose": null,
  "watch": false,
  "cache": true,
  "watchman": true,
  "testcheckOptions": {
    "times": 100,
    "maxSize": 200
  }
}