tsconfig.json

{
  "include": ["./src"],
  "compilerOptions": {
    "lib":[],
    /* Basic Options */
    "target": "ES6",                       /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    // "allowJs": true,                       /* Allow javascript files to be compiled. */
    "outDir": "./build",                        /* Redirect output structure to the directory. */
    // "declarationDir": "./build/types",
    "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    "sourceMap": true,
    // "inlineSources": true,
    "declarationMap": true,
    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */
    "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
  }
}