tsconfig.json

{
  "compilerOptions": {
    "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
    "lib": ["es6","dom"],                                /* Specify a set of bundled library declaration files that describe the target runtime environment. */
    "module": "commonjs",                                /* Specify what module code is generated. */
    "rootDir": "src",                                    /* Specify the root folder within your source files. */
    "resolveJsonModule": true,                           /* Enable importing .json files. */
    "outDir": "lib",                                     /* Specify an output folder for all emitted files. */
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
    "strict": true,                                      /* Enable all strict type-checking options. */
    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  }
}