.babelrc

{
  "plugins": [
    ["@babel/plugin-proposal-object-rest-spread", {
      "useBuiltIns": true
    }]
  ],
  "presets": [
    "@babel/preset-typescript",
    ["@babel/preset-env", {
      "targets": {
        "browsers": [
          ">1%",
          "last 4 versions",
          "Firefox ESR",
          "not ie < 9"
        ]
      },
      "exclude": ["@babel/plugin-transform-regenerator"]
    }]
  ],
  "env": {
    "es": {
      "presets": [
        "@babel/preset-typescript",
        ["@babel/preset-env", {
          "modules": false,
          "targets": {
            "browsers": [
              ">1%",
              "last 4 versions",
              "Firefox ESR",
              "not ie < 9"
            ]
          },
          "exclude": ["@babel/plugin-transform-regenerator"]
        }]
      ]
    },
    "lib": {
      "presets": [
        "@babel/preset-typescript",
        ["@babel/preset-env", {
          "modules": "commonjs",
          "targets": {
            "browsers": [
              ">1%",
              "last 4 versions",
              "Firefox ESR",
              "not ie < 9"
            ]
          },
          "exclude": ["@babel/plugin-transform-regenerator"]
        }]
      ]
    },
    "test": {
      "presets": [
        "@babel/preset-typescript",
        ["@babel/preset-env", {
          "targets": {
            "node": "current"
          }
        }]
      ]
    }
  }
}