.babelrc

{
    "env": {
        "lib": {
            "presets": [
                [
                    "@babel/preset-env",
                    {
                        "loose": true
                    }
                ]
            ]
        },
        "test": {
            "plugins": ["@babel/plugin-proposal-class-properties"],
            "presets": [
                [
                    "@babel/preset-env",
                    {
                        "loose": true
                    }
                ],
                "@babel/preset-react"
            ]
        }
    },
    "plugins": [
        ["@babel/plugin-proposal-class-properties", { "loose": false }],
        ["@babel/plugin-proposal-private-methods", { "loose": false }],
        [
            "@babel/plugin-proposal-private-property-in-object",
            { "loose": false }
        ]
    ],
    "presets": [
        "@babel/preset-typescript",
        [
            "@babel/preset-env",
            {
                "loose": true,
                "modules": false
            }
        ]
    ]
}