javascript - Transpile 验证器 esm node_modules 文件 jest

Question

我正在使用 validator library with tree-shakable esm imports有效的捆绑尺寸。

当我尝试使用 jest 测试使用 esm 模块导入的文件时，出现以下错误 -

Jest encountered an unexpected token

    This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

    By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".

    Here's what you can do:
     • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.
     • 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/en/configuration.html

    Details:

    helpers/node_modules/validator/es/lib/isEmpty.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import assertString from './util/assertString';
                                                                                             ^^^^^^

    SyntaxError: Cannot use import statement outside a module

    > 1 | import isEmpty from 'validator/es/lib/isEmpty';
        | ^
      2 | import isURL from 'validator/es/lib/isURL';
      3 | import isEmail from 'validator/es/lib/isEmail';
      4 | import matches from 'validator/es/lib/matches';

      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1350:14)
      at Object.<anonymous> (src/validator.ts:1:1)

现在我知道 jest 无法解析 ESM 模块，所以我尝试将验证程序库添加到 transformIgnorePatterns .这就是我的 jest.config.js 的样子

module.exports = {
  preset: 'ts-jest',
  roots: ['<rootDir>/src'],
  testMatch: ['**/__tests__/**/*.+(ts|tsx|js)', '**/?(*.)+(spec|test).+(ts|tsx|js)'],
  transform: {
    '^.+\\.(ts|tsx)$': 'ts-jest',
  },
  transformIgnorePatterns: ['<rootDir>/node_modules/(?!(validator/es/lib)/)'],
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx'],
};

但这没有用。

我也试过this answer并添加了用于转译的 babel，使用答案中提到的相同配置，但我仍然遇到相同的错误。

尽管测试适用于 non-ESM imports ，喜欢，

import isEmpty from 'validator/lib/isEmpty';

Answer 1

尝试将此行添加到您的 jest.config.js

module.exports = {
  ...
  transformIgnorePatterns: [
    '/node_modules/(?!(validator)/)'
  ],
  ...
}

或尝试从 package.json

更新 jest

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