javascript - 运行 Jest 测试时遇到问题 : `SyntaxError: Unexpected token <`

Question

我知道这可能之前已经发布过，但我真的很困惑为什么我的测试在我的 React 项目中不起作用。这是我的 .babelrc文件:

{
    "presets": ["react", "es2015", "stage-0"],

    "plugins": [
        "transform-runtime",
        "add-module-exports",
        "transform-decorators-legacy"
    ],

    "env": {
        "development": {
            "plugins": [
                "typecheck",
                ["react-transform", {
                    "transforms": [{
                        "transform": "react-transform-catch-errors",
                        "imports": ["react", "redbox-react"]
                    }]
                }]
            ]
        },
        "test": {
            "presets": ["es2015", "react", "stage-0"],
            "plugins": [
                "transform-runtime",
                "add-module-exports",
                "transform-decorators-legacy"
            ]
        }
    }
}

这是我在 package.json 中的 Jest 设置

  "jest": {
    "moduleFileExtensions": [
      "js",
      "jsx",
      "json"
    ],
    "moduleNameMapper": {
      "ExampleTest": "<rootDir>/app/pages/ExampleTest.js"
    },
    "moduleDirectories": [
      "app",
      "node_modules"
    ]
  },

我得到的错误是 Test suite failed to run... SyntaxError: Unexpected token < .

据我所知，它试图运行的文件中包含 JSX/ES6 代码……但它不知道如何转译这些代码？这很奇怪，因为我已经告诉它在 .babelrc 中做到这一点。 .我还为 Jest 提供了适当的 moduleDirectories .

如有任何帮助，我们将不胜感激。

Answer 1

您的 JSON 中的最后一个逗号 , 是错误的。它应该看起来像:

{"root":{
    "presets": ["react", "es2015", "stage-0"],

    "plugins": [
        "transform-runtime",
        "add-module-exports",
        "transform-decorators-legacy"
    ],

    "env": {
        "development": {
            "plugins": [
                "typecheck",
                ["react-transform", {
                    "transforms": [{
                        "transform": "react-transform-catch-errors",
                        "imports": ["react", "redbox-react"]
                    }]
                }]
            ]
        },
        "test": {
            "presets": ["es2015", "react", "stage-0"],
            "plugins": [
                "transform-runtime",
                "add-module-exports",
                "transform-decorators-legacy"
            ]
        }
    }
}}