迁移到 React 17：未捕获的引用错误：React 未定义

Question

遵循 React 网站中提到的从 React 16 迁移到 React 17 的所有步骤后 删除反应导入后

我看到以下错误

Uncaught ReferenceError: React is not defined

Babel.config.js

module.exports = function(api) {
  api.cache(true);

  const presets = [
    '@babel/preset-env', 
    ["@babel/preset-react", {"runtime": "automatic"}]
  ];

  const plugins = [
    ['@babel/plugin-proposal-class-properties'],
    '@babel/plugin-syntax-dynamic-import',
    '@babel/plugin-proposal-nullish-coalescing-operator',
    '@babel/plugin-proposal-optional-chaining',
    ["@babel/plugin-transform-react-jsx", {
      "runtime": "automatic"
    }]
  ];

  const env = {
    test: {},
    cucumber: {
      plugins: [
        '@babel/plugin-transform-regenerator',
        [
          '@babel/plugin-transform-runtime',
          {
            regenerator: true,
          },
        ],
      ],
    },
    cypress: {
      plugins: ['istanbul'],
    },
  };

  return {
    presets,
    plugins,
    env,
  };
};

开发依赖

    "@babel/plugin-transform-react-jsx": "7.23.4",
    "@babel/plugin-proposal-class-properties": "^7.5.5",
    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.12.1",
    "@babel/plugin-proposal-optional-chaining": "^7.12.1",
    "@babel/plugin-proposal-private-property-in-object": "^7.21.11",
    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
    "@babel/preset-env": "^7.24.0",
    "@babel/preset-react": "^7.23.3",

反应版本：17.0.2

React 16 到 17 的迁移我使用了以下所有步骤： https://legacy.reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html

Answer 1

这里也一样。从 React 16 升级到 React 19，我得到了

React is not defined
ReferenceError: React is not defined

所有未导入 React 的地方。 React 19 不应该再出现这种情况。我猜问题出在从 React 16 迁移到 React 19 的过程中，而且它在某种程度上是内部的。

非常感谢任何帮助！