.babelrc

{
    "presets": [
        [
            "@babel/preset-env",
            {
                "modules": false,
                "targets": {
                    "browsers": [
                        "> 1%",
                        "last 2 versions",
                        "not ie <= 8"
                    ]
                }
            }
        ]
    ],
    "plugins": [
        "@babel/plugin-transform-runtime",
        [
            "@babel/plugin-proposal-decorators",
            {
                "legacy": true
            }
        ],
        [
            "@babel/plugin-transform-modules-commonjs",
            {
                "allowTopLevelThis": true
            }
        ],
        "@babel/plugin-proposal-function-sent",
        "@babel/plugin-proposal-export-namespace-from",
        "@babel/plugin-proposal-numeric-separator",
        "@babel/plugin-proposal-throw-expressions",
        "@babel/plugin-syntax-dynamic-import",
        "@babel/plugin-syntax-import-meta",
        [
            "@babel/plugin-proposal-class-properties",
            {
                "loose": false
            }
        ],
        "@babel/plugin-proposal-json-strings"
    ],
    "env": {
        "test": {
            "presets": [
                "@babel/preset-env"
            ],
            "plugins": [
                "istanbul",
                [
                    "@babel/plugin-proposal-decorators",
                    {
                        "legacy": true
                    }
                ],
                "@babel/plugin-proposal-function-sent",
                "@babel/plugin-proposal-export-namespace-from",
                "@babel/plugin-proposal-numeric-separator",
                "@babel/plugin-proposal-throw-expressions",
                "@babel/plugin-syntax-dynamic-import",
                "@babel/plugin-syntax-import-meta",
                [
                    "@babel/plugin-proposal-class-properties",
                    {
                        "loose": false
                    }
                ],
                "@babel/plugin-proposal-json-strings"
            ]
        }
    }
}