“loose”: true is not fixing Support for the experimental syntax 'classProperties' isn't currently enabled

问题

Support for the experimental syntax 'classProperties' isn't currently enabled

I tried the solutions still get the error after re building.

Support for the experimental syntax 'classProperties' isn't currently enabled

package.json

{
  "name": "blahmodule",
  "version": "1.0.0",
  "description": "a fetch module for our project",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "./node_modules/.bin/babel src --out-file index.js"
  },
  "peerDependencies": {
    "react": "^16.6.6",
    "react-dom": "^16.6.3",
    "axios": "^0.19.0"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@babel/cli": "^7.4.4",
    "@babel/core": "^7.4.5",
    "@babel/preset-env": "^7.4.5",
    "@babel/preset-react": "^7.0.0",
    "react": "^16.8.6",
    "react-dom": "^16.8.6"
  },
  "devDependencies": {
    "@babel/plugin-proposal-class-properties": "^7.4.4",
    "axios": "^0.19.0"
  }
}

.babelrc

{
    "presets": [
      "@babel/preset-env",
      "@babel/preset-react"
    ],
    "plugins": [
        [
          "@babel/plugin-proposal-class-properties",
          {
            "loose": true
          }
        ]
      ]
  }

回答1:

I am using plugin-proposal-class-propterties and it works, here is my JSON configuration file .babelrc

{
  "presets": ["@babel/preset-env"],
  "plugins": [
    [
      "@babel/plugin-proposal-class-properties",
      {"loose": true}
    ]
  ]
}

回答2:

Try making a file babel.config.js and using module.exports to export the configuration. I also believe you don't require the loose option:

babel.config.js:

module.exports = {
  presets: ["@babel/preset-env", "@babel/preset-react"],
  plugins: ["@babel/plugin-proposal-class-propterties"]
};

来源：https://stackoverflow.com/questions/56813044/loose-true-is-not-fixing-support-for-the-experimental-syntax-classproperties