tsconfig.json

{
   "compilerOptions": {
      /* Basic Options */
      "target": "es2017", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
      "module": "commonjs", /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
      "moduleResolution": "node",
      "lib": [
         "es2015",
         "es2016",
         "es2017"
      ],
      // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
      // "sourceMap": true,                     /* Generates corresponding '.map' file. */
      "outDir": "./lib", /* Redirect output structure to the directory. */
      "rootDir": "./src", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
      "strict": false, /* Enable all strict type-checking options. */
      "esModuleInterop": false, /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
      "preserveWatchOutput": true
   }
}