要转换某些 "node_modules" 文件，您可以在配置中指定自定义 "transformIgnorePatterns"

Question

我运行 jest 测试文件并得到以下错误：

 ● Test suite failed to run

    Jest encountered an unexpected token

    Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.

    Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

    By default "node_modules" folder is ignored by transformers.

    Here's what you can do:
     • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
     • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
     • 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/configuration
    For information about custom transformations, see:
    https://jestjs.io/docs/code-transformation

    Details:

    /Users/test/dev/pm/client/node_modules/spacetime/src/index.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import Spacetime from './spacetime.js'
                                                                                      ^^^^^^

    SyntaxError: Cannot use import statement outside a module

       6 | import search from '../../assets/images/search.svg';
       7 | import Dropdown from 'react-bootstrap/Dropdown';
    >  8 | import spacetime from "spacetime";
         | ^
       9 | import languages from "../../libraries/languages/language-list";
      10 | import { Rating } from 'react-simple-star-rating';
      11 |

      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1728:14)
      at Object.<anonymous> (src/components/Mentor/MentorList.js:8:1)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.097 s

我试图通过将以下内容添加到 package.json 来修复它，但没有成功：

  "jest": {
    "transformIgnorePatterns": [
      "node_modules/(?!spacetime)"
    ]
  },

有人可以帮忙吗？

Answer 1

spacetime包主文件是ES6模块。见node_modules/spacetime/src/index.js，这是时空包exports.Thepackage.json的主文件include"main": "src/index.js".

By default "node_modules" folder is ignored by transformers.

你不需要为 jest 配置添加 transformIgnorePatterns 配置，node_modules 文件夹会被 transformers 忽略。

但这不是问题。

问题是 jest 默认不解析 es6 import/export 语句，即使它使用 babel。

Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

我们需要改造 es6 import 和 export 语法。

选项 1。Add babel config

选项 2. 使用 ts-jest 预设的笑话。

jest.config.js:

module.exports = {
  preset: 'ts-jest/presets/js-with-ts',
  testEnvironment: 'jsdom'
};

选项 3. 使用 esbuild-jest

jest.config.js:

module.exports = {
  testEnvironment: 'jsdom',
  transform: {
    '\.[jt]sx?$': 'esbuild-jest',
  },
};

要转换某些 "node_modules" 文件，您可以在配置中指定自定义 "transformIgnorePatterns"

To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config

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