.babelrc

{
  "presets": ["module:metro-react-native-babel-preset"],
  "plugins": [
    ["@babel/plugin-transform-flow-strip-types"],
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ],
    [
      "@babel/plugin-proposal-class-properties",
      {
        "loose": true
      }
    ],
    [
      "@babel/transform-runtime",
      {
        "helpers": true,
        "regenerator": false
      }
    ],
    [
      "rewrite-require",
      {
        "aliases": {
          "crypto": "react-native-crypto",
          "stream": "readable-stream",
          "_stream_duplex": "readable-stream/duplex",
          "_stream_passthrough": "readable-stream/passthrough",
          "_stream_readable": "readable-stream/readable",
          "_stream_transform": "readable-stream/transform",
          "_stream_writable": "readable-stream/writable",
          "@polkadot/wasm-crypto": "@plugnet/wasm-crypto-js",
          "@plugnet/util": "@polkadot/util",
          "vm": "vm-browserify"
        },
        "throwForNonStringLiteral": true
      }
    ]
  ]
}