我正在为我的 react 应用程序使用babel-preset-env 版本 - 1.6.1，我在 IE 上遇到错误：-对象不支持属性或方法“分配”

这是我的.babelrc :-

{
"presets": [
    "react",
    [
        "env",
        {
            "targets": {
                "browsers": [
                    "last 1 versions",
                    "ie >= 11"
                ]
            },
            "debug": true,
            "modules": "commonjs"
        }
    ]
],
"env": {
    "test": {
        "presets": [
            [
                "babel-preset-env",
                "react"
            ]
        ],
        "plugins": [
            "transform-object-rest-spread",
            "transform-class-properties",
            "transform-runtime",
            "babel-plugin-dynamic-import-node",
            "array-includes",
            "url-search-params-polyfill",
            "transform-object-assign"
        ]
    }
},
"plugins": [
    "transform-object-rest-spread",
    "transform-class-properties",
    "syntax-dynamic-import",
    "transform-runtime",
    "array-includes",
    "url-search-params-polyfill",
    "transform-object-assign"
]

}

我试过这些 polyfills：-

https://babeljs.io/docs/plugins/transform-object-assign/ https://www.npmjs.com/package/babel-plugin-object-assign

但它没有用

我正在使用语法：-

let a = Object.assign({},obj);

在我的项目中随处可见

我需要一个适用于我的项目的 polyfill。