ES2015+ 代码编译成 ES5

Babel 只转换，涉及到打包代码需要打包工具

• 旧配置

{
  "private": true,
  "scripts": {
    "build": "npm run babel && npm run min",
    "babel": "babel _.js --out-file _.es5.js",
    "min": "uglifyjs _.es5.js -o _.es5.min.js -c -m"
  },
  "devDependencies": {
    "babel-cli": "6.26.0",
    "babel-preset-es2015": "6.24.1",
    "babel-preset-stage-2": "6.24.1",
    "uglify-js": "3.17.4"
  },
  "browserslist": "last 2 versions",
  "babel": {
    "presets": [
      "es2015",
      "stage-2"
    ]
  }
}

• 新配置

{
  "private": true,
  "scripts": {
    "es": "npm run es-dev && npm run es-min",
    "es-dev": "babel _.js --out-file _.es5.js",
    "es-min": "babel _.js --out-file _.es5.min.js --minified"
  },
  "devDependencies": {
    "@babel/cli": "^7.28.3",
    "@babel/core": "^7.28.5",
    "@babel/preset-env": "^7.28.5"
  },
  "dependencies": {
    "core-js": "^3.46.0"
  },
  "babel": {
    "compact": false,
    "presets": [
      [
        "@babel/preset-env",
        {
          "useBuiltIns": "usage",
          "corejs": {
            "version": 3,
            "proposals": true
          },
          "targets": {
            "browsers": [
              "> 1%",
              "last 2 versions",
              "not ie <= 9"
            ]
          }
        }
      ]
    ]
  }
}