.babelrc

{
    "presets": [
        [
            "@babel/preset-env", {
                "targets": {
                    "browsers": [
                        "last 2 versions",
                        "ie >= 9",
                        "iOS >= 8"
                    ]
                },
                "modules": false,
                "loose": true,
                "useBuiltIns": false
            }
        ]
    ],
    "plugins": [
        ["@babel/plugin-transform-runtime", { "useESModules": true }],
        "@babel/plugin-proposal-class-properties",
        "add-module-exports",
        "transform-inline-consecutive-adds",
        "transform-merge-sibling-variables",
        "transform-minify-booleans",
        "minify-constant-folding",
        "minify-dead-code-elimination",
        "minify-guarded-expressions",
        "minify-numeric-literals",
        "minify-simplify",
        "minify-type-constructors"
    ]
}