使用Rails + Webpacker + Jest测试.js.erb文件

Question

我有一个Rails 5应用程序，它使用webpacker，文件app / javascript / packs / components / module_one.js，我试图用Jest测试。此文件包含对.js.erb文件的导入，如下所示：

// app/javascript/packs/components/module_one.js

import ModuleTwo from './module_two.js.erb'

// ...

module_two.js.erb包含以下内容：

// app/javascript/packs/components/module_two.js.erb

import ModuleOne from './module_one'

// ...

在运行webpack-dev-server时，一切都按预期工作，但是当我尝试运行纱线测试时，它会抱怨以下错误：

FAIL  app/javascript/test/module_one.test.js
  ● Test suite failed to run

    /path/to/module_two.js.erb:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import ModuleOne from './module_one'
                                                                                             ^^^^^^
    SyntaxError: Unexpected token import

      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:306:17)
      at Object.<anonymous> (app/javascript/packs/components/module_one.js:1:745)
      at Object.<anonymous> (app/javascript/test/module_one.test.js:1:124)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.545s
Ran all test suites.
error Command failed with exit code 1.

所以似乎模块没有从ES6正确转换module_two.js.erb文件，因为当我删除module_one.js的第一行时，它不会再抱怨了。

这是我目前的设置：

// .babelrc

{
  "presets": [
    ["env", {
      "modules": false,
      "targets": {
        "browsers": "> 1%",
        "uglify": true
      },
      "useBuiltIns": true
    }]
  ],

  "plugins": [
    "syntax-dynamic-import",
    ["transform-class-properties", { "spec": true }]
  ],

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

---

// package.json

{
  // ...
  "devDependencies": {
    "babel-jest": "^21.0.2",
    "jest": "^21.0.2",
    "regenerator-runtime": "^0.11.0",
    "webpack-dev-server": "^2.7.1"
  },
  "scripts": {
    "test": "jest"
  },
  "jest": {
    "roots": [
      "<rootDir>/app/javascript/test"
    ],
    "moduleDirectories": [
      "<rootDir>/node_modules"
    ],
    "moduleFileExtensions": [
      "js",
      "jsx",
      "erb"
    ],
    "transform": {
      "^.+\\.jsx?$": "babel-jest",
      "ˆ.+\\.jsx?.erb": "rails-erb-loader"
    }
  }
}

Answer 1

万一其他人碰到这个。您的.babelrc似乎缺少“es2015”预设。 Here很好地解释了这个以及使用Rails + Webpacker配置JS测试的其他问题。