tsconfig.json

{
  "files": [
    "src/index.ts",
    "src/controllers/**/*.ts",
    "src/models/**/*.ts",
    "src/data/**/*.ts",
    "src/helpers/**/*.ts"
  ],
  "compilerOptions": {
    "target": "es6",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. */
    "module": "commonjs",                     /* Specify module code generation: 'none', commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    "allowJs": true,                       /* Allow javascript files to be compiled. */
    "strict": true,                            /* Enable all strict type-checking options. */
    "noEmitOnError": true,
    /* Experimental Options */
    "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    "emitDecoratorMetadata": true         /* Enables experimental support for emitting type metadata for decorators. */
  }
}