Jest 测试在 d3 导入时失败

Question

我正在运行测试

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import { render } from '@testing-library/react';\nimport MyComponent from '../../../../components/MyComponent';\n\ntest('renders MyComponent', () => {\n  render(<MyComponent />);\n});\n

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在使用 d3 的 React 应用程序组件上，导入如下：

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import React from 'react';\nimport * as d3 from 'd3';\n

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使用命令

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react-scripts test\n

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这会在 d3 导入时产生错误：

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Jest encountered an unexpected token\n\nThis usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.\n\nBy default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".\n\nHere's what you can do:\n \xe2\x80\xa2 If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.\n \xe2\x80\xa2 To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.\n \xe2\x80\xa2 If you need a custom transformation specify a "transform" option in your config.\n \xe2\x80\xa2 If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.\n\nYou'll find more details and examples of these config options in the docs:\nhttps://jestjs.io/docs/en/configuration.html\n\nDetails:\n\n/Users/wogsland/Projects/sepia/node_modules/d3/src/index.js:1\n({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export * from "d3-array";\n                                                                                         ^^^^^^\n\nSyntaxError: Unexpected token 'export'\n

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我缺少什么？该组件在浏览器中工作正常，只是在最基本的测试中失败了。

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Answer 1

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

从上面的建议中，我们可以告诉 Jest 不要解析node_modules.

在您的jest.config.js文件中，您可以添加以下行。您可以将任何您想要的 ES 模块添加到阵列中。

const esModules = ['d3', 'd3-array', 'other-d3-module-if-needed'].join('|');

module.exports = {
  // ...
  transformIgnorePatterns: [`/node_modules/(?!${esModules})`],
  // ...
};

Answer 2

按照 Tiep Phan 的回答的提示，我将以下内容添加到我的 package.json 文件中：

"jest": {
    "transformIgnorePatterns": ["/node_modules/(?!d3|d3-array|internmap|delaunator|robust-predicates)"]
},

Answer 3

对于 D3v7 你可以moduleNameMapper像这样添加笑话：

    "moduleNameMapper": {
      "d3": "<rootDir>/node_modules/d3/dist/d3.min.js",
      "^d3-(.*)$": "<rootDir>/node_modules/d3-$1/dist/d3-$1.min.js"
    }