tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target": "es5",                          /* 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'. */
    // "lib": [],                             /* Specify library files to be included in the compilation. */
    "allowJs": true,                       /* Allow javascript files to be compiled. */
    "checkJs": true,                       /* Report errors in .js files. */
    "removeComments": true,                /* Do not emit comments to output. */
    /* Strict Type-Checking Options */
    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
    "strictNullChecks": true,              /* Enable strict null checks. */
    "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    "noUnusedLocals": false,                /* Report errors on unused locals. */
    "noUnusedParameters": false,            /* Report errors on unused parameters. */
    "noImplicitReturns": false             /* Report error when not all code paths in function return a value. */
  },
  "include": [
      "./source/javascripts/**/*"
  ],
  "exclude": [
    "node_modules",
    "vendor"
  ]
}